Method and apparatus for altering the access format of telephone calls

ABSTRACT

A telephone system and method of operation are disclosed which use a microprocessor control system (10), a speech generator (34) and speech memory (46) to automatically place calls without the need of a live operator. The telephone receives a destination telephone number and billing format information from a user. The microprocessor control system (10) alters the access format of the destination number and places the call as a direct dial telephone call. The billing format information is stored in a call record memory (11). The billing format information may later be retrieved to facilitate the billing of charges for the call to an appropriate party.

RELATED APPLICATIONS

This application is a continuation of application of 07/809,286 filedDec. 12, 1991, abandoned, which is a continuation of Ser. No.07/577,096, filed Aug. 29, 1990 and entitled "Method and Apparatus forAltering the Access Format of Telephone Calls," now U.S. Pat. No.5,113,433, issued May 12, 1992, which is a continuation application ofSer. No. 07/410,976, filed Sep. 22, 1989, now abandoned, which is acontinuation application Ser. No. 07/300,796, filed Jan. 23, 1989, nowU.S. Pat. No. 4,908,852, issued Mar. 13, 1990.

TECHNICAL FIELD OF THE INVENTION

This invention relates in general to the field of telecommunicationssystems. Specifically, the present invention relates to a method andapparatus for processing telephone calls which enhances thefunctionality of a telecommunications station in the placing of longdistance calls through the altering of the access format of calls placedat the station.

BACKGROUND OF THE INVENTION

The private ownership of pay telephone technology has provided an addedsource of revenue for a variety of businesses for some time. The actualcash collection from the coins deposited by users of pay telephonestations is an important aspect of such revenues. More recently, due totechnological advances and changes in the business climate, businesseshave been able to add income from certain long distance telephone calls.With the use of an Automated Operator Service (AOS), a private owner ofa telephone can bill users of the telephone for both inter-LATA andintra-LATA long distance calls.

While AOS systems can generate revenue where none existed before, theyare very inefficient. An AOS usually operates from a central office.Hence, in the case of an intra-LATA call, the call may have to travelhundreds of miles and finally terminate a few miles from its originationpoint. The unnecessary miles traveled through the network are expensiveand this cost is usually borne by the user through higher Long distancerates, or by the owner of the telephone through lower commissions.

In addition, private owners of pay telephones have heretofore lost aconsiderable amount of revenue because of their inability to charge forcalls placed using billing account numbers made on their pay telephones.These calls are billed directly by the primary telephone company to theaccount of the appropriate party leaving the owner of the telephonestation with no method for charging for these calls. Hence, althoughsuch calls have been made on the privately owned and maintained paytelephone, the primary telephone companies have reaped the benefit ofplacing these calls.

Therefore, a need has arisen for a telecommunications system which canautomate and simplify the processes currently handled by a traditionalAOS. Specifically, a need has arisen for a pay telephone station whichcan automatically route long distance calls without the intervention ofan outside service, and which allows the pay telephone owner to chargerevenues for the completion of a collect call, a call placed using atelephone billing account number or a call placed using a variety ofother billing access formats.

SUMMARY OF THE INVENTION

In accordance with the present invention, a telecommunications stationis provided which performs similar functions as the telephone company oran AOS, but does so locally and automatically. More specifically, asystem is provided which is interactive with the calling party and thecalled party through the use of prompting messages. These messages cansupply information or prompting to the users of the system and canthereby automatically complete calls that would otherwise require theservices of a live operator.

An important technical advantage of the present method and systemprovided is its ability to locally receive a telephone number from auser of the station and alter the access format of the number from aformat which is billed directly to a remote location to one which isbilled to the local station. Specifically, a method and system areprovided which can receive a number for a call placed as a collect call,for example, and place the call as a direct dial call. In this manner,the owner of the local telephone station may bill for calls placed usinga variety of billing access formats.

In accordance with another aspect of the invention, a telecommunicationsstation is provided which can locally store the billing informationinput by a user of the station. The call is then placed for the user asa direct dial call and the billing information is later retrieved fromstorage to enable the subsequent billing of charges for the call.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be derived byreferring to the detailed description and claims when considered inconnection with the accompanying drawings, in which like referencenumbers indicate like features through the drawings, and wherein:

FIG. 1 is a block diagram of a pay telephone station utilizing aspectsof the present invention;

FIG. 2 is a block diagram showing greater detail of portions of theblock diagram of FIG. 1;

FIG. 3 is a block diagram illustrating the process of downloading speechfiles encompassed in the present invention;

FIG. 4 is a block diagram illustrating the validation interface computersystem utilized in the present invention;

FIGS. 5a-7c are schematic diagrams showing a pay telephone stationconstructed in accordance with the present invention in detail;

FIGS. 8a-8g are flow charts showing the process of placing a collect or0+ call according to the present invention;

FIG. 9 is a flow chart showing the process of speech file generationused in the present invention;

FIG. 10 is a flow chart showing the process for downloading speech filesused in the present invention;

FIG. 11 is a flow chart showing the process used for verification oftelephone billing account numbers used in the present invention; and

FIGS. 12a-12b are flow charts demonstrating the process for voice mailused in the present invention.

DETAILED DESCRIPTION OF THE INVENTION

A more complete understanding of the present invention may be derived byreferring to the following detailed description when considered inconnection with the accompanying FIGS. 1 through 12. Like referencenumbers indicate like features throughout the drawings. In addition,reference designations for branch points in the flowcharts and forsignals contained in the schematic diagrams indicate connections whichcould not otherwise be adequately demonstrated due to space constraints.

Block Diagram of the System

FIG. 1 is a block diagram which shows the general organization of alocalized telecommunications device such as a pay telephone stationconstructed according to the teachings of the present invention.Throughout the description of the present invention, use of the terms"pay telephone", "telephone", "station" or similar terms should beconstrued in their broadest sense. The teachings of the presentinvention are applicable to all publicly accessible telecommunicationsdevices which charge for each call made whether or not the particulardevice has actual coin receipt capability. The aforementioned terms whenused herein are intended to include all such telecommunications devices.

Microprocessor control system 10 comprises a suitable digital processorsuch as a Hitachi 6309E microprocessor. System 10 serves to monitor theinput/output devices in the telephone and makes the control decisions onwhat actions are taken within the telephone circuitry.

The microprocessor 10 is included within the local pay telephone stationso that a variety of operations can occur locally at the telephone. Forexample, a pay telephone station constructed according to the presentinvention has the capability to complete long distance calls usingtelephone billing account numbers. The local station can verify thebilling account number and place the calls all using circuitry residentwithin the station. In operation, the local telephone station stores thebilling account number and places the call as a direct dial telephonecall. In this manner, the local station is billed for the call and theowner of the station may then bill the appropriate party for callsplaced using the local station. The local station can also generate andstore a record of the call which can later be retrieved to facilitatebilling of the call. All these functions are controlled locally withinthe station by microprocessor control system 10. This local controleliminates the inefficient and time consuming need for external controlat a central office or AOS.

A call record memory 11 is connected to system 10 and is used to storethe billing records of completed calls. These billing records caninclude the type of the call that was placed, the price of the call, andthe duration of the call. Microprocessor control system 10 uses a realtime clock 12 to determine what time a telephone call is originated todetermine if any discounts are applicable and to time the duration ofthe call. Operational software for the system is stored in a programmemory 14. Program memory 14 may comprise, for example, two 32 K×8static RAMS which are battery backed up to make the memory non-volatile.

A rate memory 16 is connected to system 10 and also comprises a batterybacked up static RAM module. This RAM module has the batteries containedwithin the component so that the component can be removed from one boardto another board without loss of power to the memory. In one embodimentof the present invention, rate memory 16 stores rates for the telephoneand configuration data for a particular telephone. In this embodiment,the rate for a particular call may be stored in the billing record forthe call. In an alternate embodiment, the rate for the call may beapplied in the station and the actual price of the call may be stored inthe billing record for the call. In still another embodiment, the timeof the call, the destination phone number and the time of day can bestored in the billing record for the call, and the rate for the call canbe applied at a remote location after the billing record has beentransferred out of the local station to facilitate the billing of thecall. This configuration data is programmable by the user through theuse of a PC and a rate table editing program. By using this program, theuser can enable or disable various features in a specific telephone.

A kernel memory 18 is coupled to microprocessor control system 10 andmay comprise a 16 K×8 EPROM. Kernel memory 18 is not volatile and storesa program which is used to boot up the telephone when the telephone isinitially turned on. The kernel program also contains the program toautomatically call out and redownload program or rate files if they arecorrupted.

A coin acceptor 20 is monitored by microprocessor control system 10 andcomprises a device which inputs whether a nickel, dime or quarter hasbeen deposited into the system. Microprocessor control system 10monitors coin acceptor 20 to determine if the coin acceptor mechanism isjammed. Coin return/collect system 22 is associated with acceptor 20 andis a coin escrow device which stores the coin until the decision is madeby microprocessor control system 10 whether to collect or return thecoins. When signaled by microprocessor control system 10, the coinreturn/collect system 22 mechanically routes the return of the coin orcollects the coin.

Keypad and hookswitch 24 comprises two separate inputs to microprocessorcontrol system 10. The hookswitch input of keypad hookswitch 24indicates to microprocessor control system 10 whether the handset of thetelephone is on or off the hook. When the handset is signaled to be onthe hook, the microprocessor control system 10 can terminate the call.When the hookswitch input signals microprocessor control system 10 thatthe handset is off the hook, microprocessor control system 10 startsmonitoring the keypad input 24 and the coin acceptor 20. Keypad andhookswitch 24 does not directly control the connection of the localtelephone with the telecommunications network. The keypad input ofkeypad and hookswitch 24 is a standard 3×4 matrix of switches used bythe patron to input data into the telephone.

Controlled earpiece 26 is comprised of the hearing aid compatible audiotransducer contained in pay telephone handsets, as well as a series ofanalog enabling switches and buffering amplifiers which are discussedlater with reference to the schematic diagrams. A call status detector28 monitors the received audio signals from the telephone line and isused to monitor the status of the telephone line. Call status detector28 determines whether the line is busy, ringing or whether the call hasbeen intercepted by detecting a special information tone (SIT). Thefunctionality of call status detector 28 is fully described in U.S. Pat.No. 4,405,833 issued to Cave et al.

Modem 30 is a 1200 BAUD modem which can transfer phase shift key datafrom the microprocessor control system and receive phase shift keyinformation from the telephone line. Modem 30 is a full duplex modemwhich is used for communicating accounting data and status data from thetelephone. Modem 30 is also used for loading program memory or commandsfrom a host computer or transmitting to a host computer data from thetelephone. Such data from the telephone could include coin totals,billing records or error conditions.

Mouthpiece 32 comprises a standard microphone contained in the telephonehandset also including controlled earpiece 26, as well as a system ofenabling switches and amplification circuitry. Microphone statusdetector 33 is used to monitor voice activity at the microphone. Themicroprocessor control system 10 can monitor this detector 33 in part todetermine the status of the call. Speech synthesizer 34 comprises memoryand control circuits which contain custom recorded speech phrases.Microprocessor control system 10 can select which of these phrases touse and play these phrases over the telephone line or into earpiece 26.Speech synthesizer 34 may comprise a General Instrument SP0264. Themessages generated by speech synthesizer 34 may be used to prompt a userof the terminal or a called party. In an alternate embodiment of thepresent invention, a telephone terminal with video capabilities maygenerate simultaneous video prompts in conjunction with the speechmessages. A further embodiment of the present invention uses exclusivelyvideo messages to prompt the user of the local station.

A DTMF generator 36 is coupled to microprocessor control system 10 togenerate the dual tone multi-frequency signals which enable thetelephone to place a call. DTMF generator 36 may comprise, for example,a Sharp 4089 DTMF generator. Incoming ring detector 37 is a componentwhich samples the incoming telephone line and detects the ring signalson that line. A telephone line interface 38 is coupled to microprocessorcontrol system 10 and interfaces between the telephone central officeand the remainder of the circuitry of FIG. 1. Telephone line interface38 comprises multiple components which are used to interface with thestandard network telephone line. Telephone line interface 38 convertsthe TIP and RING inputs into a four wire audio output, and also containscircuitry necessary to take the telephone on or off hook.

Intellistar transmit module 40 is coupled between controlled mouthpiece32 and telephone line interface 38 and comprises an additional speechsynthesizer and a DTMF generator which injects additional audio signalsinto the transmit path. Intellistar receive module 42 comprises anattenuated audio path for use in voice mail applications, an additionalDTMF receiver to detect DTMF tones transmitted through the telephoneline and an additional call status detector. Intellistar systemcontroller 48 may comprise, for example, a GTE 65SC151 microcomputer andperipheral support components. Intellistar system controller 48 controlsthe functions of Intellistar transmit module 40 and Intellistar receivemodule 42.

FIG. 2 illustrates a block diagram showing greater detail of thetransmit module 40 and receive module 42 of FIG. 1. The dottedconnection lines between elements in FIG. 2 represent control signalpaths and the solid lines represent audio signal paths. Controlledearpiece 26 and mouthpiece 32 on FIG. 2 are contained within the handsetof the telephone as previously described. Mouthpiece 32 is coupled to aspeech record/playback generator 44 which may comprise a Toshiba TC-8830adaptive delta PCM speech generator which can record audio tones orvoices and store them in a speech memory RAM 46. Speech memory RAM 46 isa battery backed static RAM non-volatile memory. Intellistar transmitmodule 40 further comprises a call status tone generator 56 whichgenerates dial tones, ring back signals, or busy signals and presentsthem to the telephone line interface 38 and to the controlled earpiece26.

Intellistar transmit module 40 further comprises a summer 58 which takesplayback audio signals from speech record/playback generator 44, callstatus tone generator 56 and transmitted signals from modem 30 and sumsthem together and outputs them to transmit line 102. A second summerdevice 60 sums the signal on transmit line 102, signals from DTMFgenerator 36 (FIG. 1) mouthpiece 32 and speech synthesizer 34 (FIG. 1)and outputs the combined signals to telephone line interface 38.

System controller 48 is controlled by the main microprocessor controlsystem 10. System controller 48 interfaces with modem 30 as shown onFIG. 2 and with call status detector 50, DTMF receiver 52, and switcharray 54, which are portions of Intellistar receive module 42. Callstatus detector 50 is used for busy signal detection and may comprise aSilicon Systems 75T982 detector. DTMF receiver 52 may comprise a SiliconSystems 75T202 receiver. Switch array 54 comprises a group of discreteanalog audio switches coupled to outputs from transmit module 40 andfrom an attenuator 62, in order to control the audio path to controlledearpiece 26. Switch array 54 comprises four discrete audio switches andthe four paths are joined together using op amps so that the paths maybe summed together or turned on or off independently.

Attenuator 62 provides an attenuated path for the received audio throughswitch array 54 into controlled earpiece 26. Attenuator 62 lowers themagnitude of the audio signal approximately 20 dB in order to reduce thevolume of a busy signal from the telephone system, for example, to allowa prerecorded speech message to be transmitted over the attenuated busysignal. By having the output of summer 58 into switch array 54 and thepath from telephone line interface 38 through attenuator 62 into switcharray 54, it is possible to have two audio sources transmitted tocontrolled earpiece 26 at the same time with one of the audio signalsbeing attenuated approximately 20 dB.

The operation of the present invention depicted in the block diagrams ofFIGS. 1 and 2 is best understood when examined in the context ofinteractive use of the invention with a patron. A basic introduction tothe interaction of the various components of the invention can beachieved through a step by step analysis of the making of a basic coincall by using a telephone constructed in accordance to the teachings ofthe present invention.

When a patron desires to place a coin call using the localtelecommunications station, the patron removes the handset from thehookswitch 24. Microprocessor control system 10, at this time, would berunning a constant control program testing the hookswitch input 24. Whenmicroprocessor control system 10 determines that the handset has beenremoved from hookswitch 24, it clears an audio path from telephone lineinterface 38 to controlled earpiece 26. Typically, the patron would thendial a telephone number using keypad 24. Software running inmicroprocessor control system 10 then determines when all of the digitsof the number have been collected. The software then looks to ratememory 16 to determine a rate for that call using the digits that thepatron dialed. Alternatively, if the rating of the call is to beaccomplished outside the phone, microprocessor control system 10 wouldrecord the destination number and the time of the day for the call.

Microprocessor control system 10 then activates speech synthesizer 34and audio switches 54 in order to play a speech message to the patronthrough controlled earpiece 26 to inform the patron of how much money heneeds to input in order to place the call. As discussed previously, inthe alternative, the prompting messages could also be in video form orin a combination of both audio and video messages. Through the remainderof the description of the invention, the functioning of the variousaspects of the invention will be described in conjunction with theembodiment using solely audio prompts. It should be understood that allalternate embodiments described are intended to be included within thescope of the teachings of the present invention.

As the patron puts money into coin acceptor 20, coin acceptor 20 gives asignal to microprocessor control system 10 as to how much money has beenreceived. At any point, if the patron replaces the handset back on hookswitch 24, microprocessor control system 10 would activate coin returncollect 22 to return the patron's money out the return slot.

Once the patron has entered enough coins, microprocessor control system10 activates speech synthesizer 34 and audio switches 54 to play aspeech message which thanks the patron. The microprocessor controlsystem 10 then uses the telephone line interface 38 to take thetelephone line off the hook and causes DTMF generator 36 to dial thenumber. Microprocessor control system 10 then activates call statusdetector 28 to determine when the call destination has answered thecall. When call status detector 28 determines that the call has beenanswered, microprocessor control system 10 activates audio switches 54to establish an audio path through telephone line interface 38 tocontrolled earpiece 26. Microprocessor control system 10 also thenactivates mouthpiece 32 and establishes a transmission path throughtelephone line interface 38. When the patron replaces the handset onhookswitch 24, microprocessor control system 10 then terminates the callby taking the telephone line interface 38 back on hook. The system ofFIGS. 1 and 2 also can be used to complete a variety of other typetelephone calls, such as credit card or collect calls, as will besubsequently described.

Speech File Downloader

FIG. 3 is a diagram showing the capability of the system constructedaccording to the teaching of the present invention to download speechfiles to be used by the telephone to prompt or give information to thepatron during ordinary use of the telephone. FIG. 3 shows the recordingprocess, the digitization process and the downloading process of thespeech files into the telephone. It further shows how the telephone usesthe downloaded speech files.

As shown on FIG. 3, the speech process starts by recording a human voiceon magnetic tape via a tape recorder 70. Tape recorder 70 plays therecorded audio signals into a audio digitizer 72. Audio digitizer 72takes the analog audio signals recorded and digitizes those signals andfurther organizes the digitized signals into speech files. The audiodigitizer 72 may use a Toshiba 8830 digitizer to digitize the data andorganize the speech files in an adaptive delta PCM format. The speechfiles are then transferred to a disk file 74 which may be physicallytransferred to a host computer 76. Host computer 76 may be an IBM PCstyle computer which is connected through telephone lines to a centraloffice 78. Host computer 76, by running a special program called INET,can then download the speech file data through the telephone lines. INETis a commercially available software package from INTELLICALL, INC.which allows the speech files to be downloaded to a particular paytelephone through central office 78. Although FIG. 3 shows host computer76 being connected to an individual telephone 80 through central office78, central office 78 is not a necessary part of the data flow. Hostcomputer 78 can be directly connected to any individual telephone 80.

Inside the individual telephone 80, the data is received by the modem 30controlled by microprocessor control system 10, as described inconjunction with FIG. 1. Microprocessor control system 10 runs a programresident in program memory 14. This program receives the data andtransfers it to speech memory 46. This allows speech generator 44 toaccess the data and play the correct phrases during operation oftelephone.

The Validation Interface

FIG. 4 shows a block diagram of the validation interface computersystem. This aspect of the invention is used by a telephone in the fieldto call in and connect to a high speed data link in order to validate atelephone billing account number that has been input by a patron.Individual telephone 80, shown in FIG. 4, calls in to a number which isstored in rate memory 16 (FIG. 1) through the central office 78 toconnect to a validation interface computer system 84. Individualtelephone 80 then uses modem 30 to communicate with a similar modemcontained within the validation interface computer system 84. Validationinterface computer system 84 then requests the telephone to transmit theinformation about the call. This information includes the destinationnumber, the telephone billing account number and the identificationnumber of the telephone. The validation interface computer system 84 hasthe capability to handle up to 32 incoming telephones.

Validation interface computer system 84 then takes the data receivedfrom the telephone and changes the format of the information and sendsit out through a packet assembly and disassembly device (PAD) 86. PAD 86transmits the data over the high speed data link using a 9600 BAUD modem88. The modem 88 then transmits the data over high speed data linescommercially available for lease from long distance carriers whichsupply a validation data base service 90. Validation data base service90 then determine if the billing account number transmitted is a validor invalid number and transmits that information back through modem 88and PAD 86. Validation interface computer system 84 then changes theformat of the message back to a format individual telephone 80 canunderstand and transmits the data to the telephone 80. The telephonethen terminates the communication with the validation interface computersystem 84. Validation interface computer system 84 records in a log file92 information about the transaction. The information stored in log file92 is used to verify billing and create a data base of valid and invalidtelephone billing account numbers.

FIG. 4 demonstrates an important technical advantage of the presentsystem. If the telephone 80 and the validation interface computer system84 have established contact, the validation process occurs without thenecessity of a central office providing special signalling, verificationor billing. In prior systems, the validation function has been done inthe central office. By placing the validation process circuitry in theindividual telephones, an entire step in the validation process iseliminated.

System Schematic Diagrams

FIGS. 5a-b, 6a-b, and 7a-c are more detailed schematic representationsof the telephone terminal represented in block diagrams in FIGS. 1 and2. Referring to FIG. 5a, several of the components which comprisemicroprocessor control system 10 are represented. Component 10a shown onFIG. 5a may comprise a Hitachi 6309E microprocessor chip. Microprocessor10a is the system controller for the phone. It controls the input/outputdevices and also communicates to slave processors in the system.

Microprocessor 10a has its inverse HALT signal connected to a +5 voltpower supply. Microprocessor 10a is also connected to an inverse RESETsignal. The inverse RESET signal is generated by the power supply and isused to hold all the logic systems in a reset state until the powersupply has stabilized. The TSC signal is connected through a resistor100 to ground. An inverse NMI signal is connected to +5 volt powersupply through resistor 102. An inverse FIRQ signal is also connectedfrom microprocessor 10a to a +5 volt supply through a resistor 104. Aninverse IRQ signal is also connected to a +5 volt supply through aresistor 106. The inverse FIRQ and inverse IRO signals are also used inother places in the telephone and will be represented by the samesymbols throughout the schematic diagrams shown in FIGS. 5a through 7b.The inverse R/W signal, the E signal, and the Q signal serve to couplemicroprocessor 10a with a custom gate array 10d. Microprocessor control10a also drives address lines A0-A15 and data lines D0-D7.

Address lines A0-A13 and data lines D0-D7 serve to couple microprocessor10a with kernel memory 18. Kernel memory 18 may comprise a 16 K×8 27C128EPROM manufactured by Texas Instruments. As shown on FIG. 5a, kernelmemory 18, in addition to address lines A0-A13 and data lines D0-D7, iscoupled to an inverse PGM signal and a VRP signal which are both coupledto a +5 volt supply. Kernel memory 18 is selected using an OE signalwhich is coupled to the inverse OE pin on the chip and an inverse EPROMsignal which is coupled to the inverse CS signal.

Kernel memory 18 stores the program that enables the phone to boot up aswell as diagnostic routines to enable the phone to tell if all requiredsoftware is operational. Kernel memory 18 also stores a program thatallows the phone to down load a new operating program from a remote hostcomputer should the operational software stored locally in the phonebecome disrupted.

The inverse OE signal and EPROM signal are both generated by gate array10d. Gate array 10d comprises an application specific integrated circuitwhich provides chip select signals and control signals for a variety ofcomponents in the system. Gate array 10d may comprise an SGS ThompsonHB54M custom 2000 gate array in a 68 PLCC package. Rather thanimplementing the glue logic necessary for the operation ofmicroprocessor control system 10 using discrete logic gates, the systemis greatly simplified by having the necessary control signals generatedby the single gate array 10d.

Address lines A0-A12 and data lines D0-D7 couple microprocessor 10a torate memory 16 as shown in FIG. 5a. Rate memory 16 may comprise a DallasSemiconductor DS1225 battery backed static RAM. This non-volatile memorydevice is capable of being reprogrammed remotely and stores rateinformation and location specific operating parameters. Rate memory 16uses inverse WE signal which is connected to the inverse WE pin on thechip. Rate memory 16 also uses OE signal which is connected to theinverse OE pin on the rate memory 16 chip. Inverse EEROM signal isconnected to the inverse CS pin on rate memory chip 16. These signalsall serve to enable rate memory 16 and are all generated by gate array10d.

Microprocessor control system 10 further comprises scratch pad memorychip 10f which may comprise, for example, a Hitachi 6264 8 K×8 randomaccess memory chip. As shown in FIG. 5a, address lines A0-A12 anddatalines D0-D7 connect scratch pad memory 10f with microprocessor chip10a. Scratch pad memory 10f uses inverse WE signal which is connected tothe inverse WE pin of the chip. Inverse OE signal is connected to theinverse OE pin on the chip. Inverse RAM signal is connected to theinverse CS pin on scratch pad memory 10f. These signals are used toenable scratch pad memory 10f and are all generated by gate array 1d.Scratch pad memory 10f is used by microprocessor 10a as a stack RAM forstoring registers during interrupts, intermediate results and othertransient data storage.

As discussed previously, address lines A2-A15 couple microprocessor 10ato gate array 10d. As shown in FIG. 5a, gate array 10d generates controlsignals BA14, inverse EPROM, inverse EEROM, inverse RAM, inverse OE,inverse 68X0, CK306, inverse EXPBUS, inverse BRAM1, inverse RDST,inverse CMDL, inverse WE, inverse 8255, inverse BRAM2, WDOG, inverseOL1, SPARE, OL2 and inverse ALD. Gate array 10d communicates withmicroprocessor 10a through address lines A2-A15 and through a R/inverseW signal, an E signal and a Q signal. The RST2 pin is connected toground.

BA14 is a control signal which is transmitted by gate array 10d to astatic RAM 11/14a which is shown on FIG. 5b. Inverse EPROM is a chipselect signal generated by gate array 10d and transmitted to kernelmemory 18. Inverse EEROM and inverse RAM are similar chip select signalstransmitted to rate memory 16 and scratch pad memory chip 10f,respectively. The inverse OE signal is generated by gate array 10d toselect these three elements as well as other input/output elements ofthe system. The inverse 68X0 signal is a chip select signal generated bygate array 10d and transmitted to a counter timer 10b and a universalasynchronous receipt transmit device 10c (UART). The CK306 signal is aclock signal also generated by gate array 10d and transmitted to countertimer 10b. The inverse EXPBUS signal is a control signal transmitted toan expansion bus 10g. The inverse BRAM1 and inverse BRAM2 signals arecontrol signals used to enable RAM chips 11/14a and 11/14b. The inverseRDST and inverse CMDL signals are control signals generated by the gatearray 10d and transmitted to the call status detector 28. The inverse WEsignal is transmitted throughout the system and is used to write datainto any memory or I/O device. Inverse 8255 is a chip select signal fora programmable I/O 10h. The WDOG signal is generated by the gate array10d and transmitted to the power supply. The WDOG signal is asupervisory signal which is used to inform the power supply thatsomething is wrong with the system and it needs to be shut off and thenpowered up again. The inverse OL1 signal is a chip select signaltransmitted to programmable I/O 10k. The SPARE signal is a controlsignal transmitted by gate array 10d to real time clock 12. The OL2signal is a control signal which is used to latch an address into thereal time clock 12. The inverse ALD signal is a control signal used tolatch an address into the speech synthesizer 34.

The CLKII pin on gate array 10d is connected to an oscillator 108 whichcomprises a resistor 110, an inverter 112, and a crystal 114 connectedin parallel. Each node of this parallel connection is connected toground through capacitors 116 and 118, respectively. The output node isconnected to the CLKII pin on gate array chip 10d through an inverter120 as shown in FIG. 5a. Oscillator 108 serves as the system oscillatorand may use, for example, an 11.0592 megahertz crystal to provide theclock signal for microprocessor 10a.

Microprocessor control system 10 further comprises a gate array 10i alsoshown on FIG. 5a. Gate array 10i comprises control logic which isactually resident on the same chip as gate array 10d. The gate array 10icomprises control logic which services a conceptually distinguishableportion of the system and hence is schematically represented as adiscrete element. Gate array 10i generates control signals for theIntellistar system controller 48, the controlled earpiece 26 and thespeech synthesizer 34.

Gate array 10i uses control signals VRES to reset the Intellistar systemcontroller 48. Signals LA1, VDATA, inverse VWRB and inverse VRDB areused to transmit commands to the Intellistar system controller 48 orreceive status information. HNDEN and MICEN signals are generated bygate array 10i to enable the earphone 26 and mouthpiece 32,respectively. An inverse SPRESET signal is generated by gate array 10ito reset microphone status detector 33.

The interface between microprocessor control system 10 and keypad andhookswitch 24 is accomplished by an additional gate array 10j, alsoshown on FIG. 5a. Gate array 10j also comprises control logic which isresident on the same chip as gate array 10d. It is also shown as adiscrete element because it generates control signals for a conceptuallydistinct portion of the system. Gate array 10j generates signals COL3,COL2 and COL1 through resistors 122, 124 and 126, respectively. An RCVENsignal is generated by gate array 10j and is transmitted throughinverter 128 to the controlled earpiece 26 to disconnect the telephoneline from the earpiece 26 to let other audio information into thecontrolled earpiece 26. Gate array 10j also generates an VCLK signalwhich is an additional interface signal transmitted to the Intellistarsystem controller 48. A SPEN signal is generated by the gate array 10jto control the connection from the speech synthesizer 34 through thetelephone line interface 38.

Microprocessor control system 10 further comprises a programmable I/Ochip 10k also shown on FIG. 5a. Programmable I/O chip 10k comprises aSignetics 5090 addressable 8 bit latch with high current outputssuitable for driving relays. Programmable I/O chip 10k uses signals D0,A0, A1 and A2 to communicate with microprocessor 10a. Programmable I/Ochip 10k is set to a known state by inverse RESET signal and is selectedby the inverse OL1 signal generated by gate array 10d. In addition, asshown in FIG. 5a, programmable I/O chip 10k generates COLLECT and RETURNsignals which when connected with pull up resistors 130 and 132 to a +5volt supply, drive the mechanisms in the coin return/collect 22. TheCOLLECT and RETURN signals are input into a SGSL298 Relay Driver whichpowers a solenoid which electromechanically enables the return or thecollection of coins placed in the coin acceptor 20. Programmable I/Ochip 10k also communicates with the call status detector 28 using theSETCMD signal and and the CLEAR signal. Programmable I/O chip 10k alsogenerates an inverse ONHOOK signal which drives relay resident intelephone line interface 38b.

Further components of microprocessor control system 10 are shown in thecontinuation of the schematic diagram shown in FIG. 5b. Microprocessorcontrol system 10 further comprises a counter/timer 10b. Counter/timer10b may comprise, for example, a Hitachi 6340 counter/timer chip. Thischip uses the clock signal CK306 generated by gate array 10d coupled tothe inverse C1 pin. The inverse C3 and inverse G2 pins are coupled tocall status detector 28. The inverse RESET pin is connected to theinverse RESET signal which is generated by the power supply. The ENABLEpin is connected to the E signal. The inverse CSO pin is connected tothe inverse 68X0 control signal generated by gate array 10d. The CS1pin, RS2 pin, RS1 pin and RSO pin are coupled to address lines A3, A2,A1 and A0, respectively. Counter/timer 10b is also coupled to datalinesD0-D7. The inverse IRQ pin is connected to inverse IRQ interrupt signal.

An output O1 of counter/timer 10b is coupled to an RXCLK and a TXCLK pinon UART 10c. UART 10c may comprise, for example, a Hitachi 6350universal asynchronous receipt transmit device. The RS pin of UART 10cis coupled to the A0 address line signal. The CS0 and CS1 pins arecoupled to the A4 address line signal. The E pin is coupled to the Esignal and the R/inverse W pin is connected to the R/inverse W signal.The inverse CS2 pin is connected to the inverse 68X0 control signalgenerated by gate array 10d. UART 10c is also coupled to datalinesD0-D7. The inverse IRQ pin is connected to the inverse IRQ interruptsignal. UART 10c generates the RXD signal and the TXD signal from itsRXD pin and TXD pin, respectively. These signals couple UART 10c to agate array 10e.

Gate array 10e comprises logic circuitry which is also actually residenton the same chip as gate array 10d. Gate array 10e transmits a signalTXDM and receives a signal RXDM in order to communicate with modem 30.Gate array 10e is also coupled to an RS232 jack through which signalsCCTX and CCRX may be transmitted and received to communicate with anexternal computer.

Microprocessor control system 10 further comprises an expansion busbuffer 10g. Expansion bus buffer 10g may comprise, for example, an HC646bus driver chip. Expansion bus buffer 10g buffers the data bus toprevent excessive loading on the bus because of so many components beingattached to it. Expansion bus buffer 10g is connected through its A setof pins to data lines D0-D7. Expansion bus buffer then transmits datasignals D0'-D7' through its B set of pins. The D0'-D7' signals are usedto couple chip 10g with call status detector 28 and programmable I/O 10hwhich is shown on FIG. 6a. Expansion bus buffer 10g has its DIR pinconnected to the inverse EXPBUSP signal which enables the chip totransmit data. It further has its CAB pin connected to the E signalwhich is used for timing purposes.

The SETCMD, inverse RDST, inverse CMDL, inverse TONEDET, CMDFLG, STATFLGand CLEAR signals are all used to interface with call status detector28. Call status detector 28, as previously discussed, is a circuit of atype which is fully described in U.S. Pat. No. 4,405,833 issued to Caveet al.

Real time clock 12 is also shown on FIG. 5b, and may comprise, forexample, a Motorola 146818A real time clock chip. Real time clock 12 isused to store the year, month, week, day, time of day and is also usedto generate other timing functions. Real time clock 12 is connected tothe D0'-D7' signals at its AD0-AD7 pins. The V_(cc) pin is connected toa VRAM signal as is the PS pin. The VRAM signal is a battery powersupply in the system which powers the real time clock 12 even when thereis a loss of external power to the phone. The inverse CE pin and theCKPS pin are connected to ground. The ALE pin is connected to the OL2signal and the DS pin is connected to the SPARE signal. The R/inverse Wpin is connected to the R/inverse W signal. The inverse RES pin isconnected to the inverse RESET signal. The inverse IRQ pin is connectedto the inverse FIRQ signal. The OSC1 and OSC2 pins are connected to anoscillator 136 comprising crystal 138, resistors 140 and 142, andcapacitors 144, 146 and 148 connected as shown in FIG. 5b. Oscillator136 runs at 32.768 kilohertz and is used by real time clock 12 to keeptrack of time.

The call record memory 11 and program memory 14 are resident on chips11/14a and 11/14b shown in FIG. 5b. Chip 11/14a and chip 11/14b maycomprise, for example, Hitachi 62256 CMOS static RAMs. They consist of32 K×8 memory locations. The operating software for the system and thecall records are both stored on these chips.

Both chips 11/14a and 11/14b are connected to a VRAM power supplysignal. By using the VRAM signal, RAM 11/14a and RAM 11/14b both becomebattery backed random access memory chips which allows fornon-volatility of the memory and greater system realiability in theevent of an external power failure. RAM 11/14a is write enabled by theinverse WE signal connected to its inverse WE pin. The RAM 11/14a isselected by the inverse BRAM2 signal coupled to its inverse CS pin. TheOE pin is connected to the inverse OE signal. RAM 11/14a is coupled toaddress lines A0-A13. Its A14 pin is connected to the BA14 signal. TheBA14 signal is used to divide the memory space on chip 11/14a into two16 K×8 blocks. This allows microprocessor 10a to address more than 64 Kmemory locations by banking in these two 16 K blocks. Chip 11/14a iscontrolled by the BA14 signal, the inverse BRAM2 signal, the inverse WEsignal and the inverse OE signal all of which are generated by gatearray 10d. Chip 11/14a is coupled to microprocessor 10a throughdatalines D0-D7.

The second RAM 11/14b is write enabled by the inverse WE signal which iscoupled to its inverse WE pin. The inverse CS pin is connected to theinverse BRAM1 signal which is used to select RAM 11/14b. Inverse BRAM1and inverse WE are both signals generated by gate array 10d. The inverseOE pin is connected to the inverse OE signal which is an additionalcontrol signal also generated by gate array 10d. RAM 11/14b is alsocoupled to microprocessor 10a through address lines A0-A14 and datalines D0-D7.

Referring to FIG. 6a, further components of the block diagram of thepresent invention shown in FIG. 1 are shown in schematic form. A furthercomponent of microprocessor control system 10 is represented on FIG. 6aby programmable I/O 10h. Programmable I/O 10h may comprise, for example,a Toshiba 82C55 programmable input output device. Programmable I/O 10his used to read data from peripheral devices and to communicate thatdata and other status information to the microprocessor 10a.

Programmable I/O 10h has its data pins D0-D7 connected to datalinesignals D0'-D7' respectively, which are transmitted by expansion busdriver 10g shown on FIG. 5b. Programmable I/O 10h has its RESET pincoupled to the RESET signal which is used to hold the device in a knownstate during a system reset sequence. The inverse RD pin is coupled tothe inverse OE signal, the inverse WR pin is coupled to the inverse WEsignal and the inverse CS signal is coupled to the inverse 82SS signal.These three control signals are generated by gate array 10d.Programmable I/O 10h further has its A0 pin connected to the A0 addressline signal and its A1 pin connected to the A1 address line signal.These address line signals couple programmable I/O 10h to microprocessor10a shown on FIG. 5a.

Programmable I/O 10h has its PCO pin coupled to the inverse HNDSETOKsignal which couples programmable I/O 10h to the mouthpiece 32 shown inFIG. 6b. The inverse HNDSETOK signal is used to communicate theoperational status of the handset of the phone. The PB1 pin is coupledto the inverse TONEDET signal and the PB2 pin is coupled to the CMDFLGsignal. The PB3 pin is coupled to the STATFLG signal. These threesignals are control signals generated by call status detector 28.

The PB4 pin of programmable I/O 10h is coupled to the inverse RINGsignal. The inverse RING signal is a status signal generated by incomingring detector 37 to communicate the fact that an incoming ring has beendetected. The PBS pin is coupled to the SBY signal. The SBY signal isgenerated by the speech synthesizer 34 to inform the microprocessor thatthe speech synthesizer is speaking. The PB6 pin is coupled to theREVERT+signal which is a status signal generated by telephone lineinterface 38 to indicate there is positive loop current in the telephoneline.

The PA1 and PA0 pins of programmable I/O 10h are connected throughresistors 152 and 154 to components which function as coin acceptor 20shown on FIG. 1. Coin acceptor 20 comprises decoder chip 156 and diodes158 and 160 coupled as shown in FIG. 6a.

The PC5 pin is coupled to the inverse MINT signal which is an interfacesignal generated by Intellistar system controller 48. The PC3 pin iscoupled to the MICDET signal. The MICDET signal is generated by themicrophone status detector 33 to indicate activity at the local handset.The PC2 pin is coupled to the VDATA signal. The VDATA signal is aninterface signal which is used to receive status data from theIntellistar system controller 48. The PC1 pin is coupled to theREVERT-signal which is generated by the telephone line interface 38 toindicate loop current in the minus direction.

The PA3 pin is coupled through a resistor 164 to the HANDSET signal andkeypad hookswitch 24. The HANDSET signal is generated by the keypadhookswitch 24 shown on FIG. 1 and informs the system that a patron hasremoved the handset from its hook or that the patron has returned thehandset to the hook. The PA4, PA5, PA6 and PA7 pins are coupled to theROW1, ROW2, ROW3 and ROW4 signals used by keypad hook switch 24 todecode which key a patron has pressed. These signals, along with theHANDSET signal, are coupled to a connector 166 which comprises a portionof keypad hookswitch 24.

Also shown in FIG. 6a is a schematic representation of DTMF generator 36shown in FIG. 1. The DTMF generator 36 comprises a latch 168 and a DTMFgenerator chip 170. Latch 168 may comprise, for example, an HC374Octolatch. DTMF generator chip 170 may comprise, for example, a Sharp4089. Chip 170 is coupled to a crystal 172 which operates at 3.57 MHzand is used for timing purposes. Latch 168 has its D lines connected todataline signals D0'-D7' generated by expansion bus buffer 10g. Latch168 is also coupled to inverse DTMFEN signal which is generated by gatearray 10d. The Q pins of latch 168 are coupled to the C1-C4 pins andR1-R4 pins of DTMF generator 170. In operation, DTMF generator 36latches data generated by the expansion bus buffer 10g using latch 168controlled by the control signal inverse DTMFEN. The latched data isused to select a tone pair to be generated by DTMF generator chip 170.This tone pair is transmitted to the TONE pin of chip 170 to the phoneline and is used by the phone to dial into a central office. The DTMFgenerator chip 170 also generates a TONEOUT control signal which is usedto reduce the amplitude in the audio path while a DTMF tone is beingtransmitted.

The TONE pin of chip 170 is coupled to summer 60 and to ground throughresistor 174 contained in summer 60. Summer 60 is an analog summingdevice which combines tone and speech signals which are beingtransmitted from the phone. DTMF generator chip 170 is connected to again stage 96 through capacitor 176. Gain stage 96 comprises resistors178 and 180 and an op amp 182 connected as shown in FIG. 6a. The SPOUTsignal enters summer 60 through a resistor 184. The SPOUT signal carriesspeech signals transmitted to summer 60 from the speech synthesizer 34shown in FIG. 1. The SPOUT signal is transmitted through a low passfilter 94 which comprises capacitor 186, resistor 188, capacitor 190 andop amp 192 coupled as shown in FIG. 6a. Low pass filter 94 takes theSPOUT signal transmitted by the speech synthesizer 34 and filters outthe high frequency components. The signal then travels through capacitor194 where the SPEECH signal is transmitted to controlled earpiece 26shown in FIG. 6b from a node 196. Node 196 is coupled to an analogswitch 98 through resistor 198. Analog switch 98 is controlled by theSPEN signal, which when active, allows the filtered SPOUT signal to betransmitted to node 200. At node 200, the amplified signal from the TONEpin of chip 170 is coupled to the SPOUT signal after passing throughcapacitors 202 and resistor 204. In addition, the signal transmitted bytransmitting 102 from the Intellistar transmit module 40 (FIG. 2) isalso coupled to node 200. The combined signals travel from node 200through a gain stage 100 which comprises an op amp 206 and resistors 208and 210 coupled as shown in FIG. 6a. The summed signal from summer 60 isthen transmitted to the phone line through the telephone line interface38 shown on FIG. 6b.

Referring now to FIG. 6b, a schematic representation of the circuitryrequired for controlled earpiece 26 is depicted. Controlled earpiece 26includes a hearing aid compatible speaker 216 coupled to a hand setconnector 218. The audio signals are transmitted to the speaker 216through amplifier stages indicated generally at 232 and at 234.Amplifier stage 232 comprises resistors 220, 222 and 226, capacitor 228and op amp 224 coupled as shown in FIG. 6b. Amplifier stage 234comprises resistors 236 and 238 and op amp 240 coupled as shown in FIG.6b. Amplifier stages 232 and 234 are separated by analog switch 230which is controlled by the HNDEN control signal generated by gate array10i. The HNDEN signal is used in conjunction with analog switch 230 tocompletely disable the earpiece 26 and not allow any audio signals toreach the patron. In contrast, a second analog switch 266 is controlledby the RCVEN signal generated by gate array 10j and only cuts off audiosignals coming from the telephone line interface 38. The SPEECH and DTMFsignals may then be transmitted to the controlled earpiece 26 withoutinterference from audio signals coming from the telephone line. TheSPEECH and DTMF signals which carry audio signals from the speechsynthesizer 34 and the DTMF generator 36, respectively, are accordinglycoupled to the input of amplification stage 234 immediately behindanalog switch 266 which is coupled to the RCVEN signal.

The mouth piece assembly 32 comprises a transducer 242 which is attachedto handset connector 218. The signal from the hand set is used togenerate the inverse HNDSETOK signal which is transmitted by way ofresistors 244 and 246 to programmable I/O 10h shown in FIG. 6a. Aresistor 248 connected to a +12 volt supply completes a voltage dividerused to bias the inverse HNDSETOK signal as shown in FIG. 6b. The audiosignal is transmitted through an amplifier stage 250 comprisingcapacitor 252, resistor 254, resistor 256 and resistor 258 and op amp260. After passing through an analog switch 262 and capacitor 264, theMIC signal is transmitted to the summer 60 shown in FIG. 6a where itenters the audio path at node 200. Analog switch 262 is controlled bythe MICEN control signal generated by gate array 10i in order to enableor disable the microphone 32.

As shown in FIG. 6b, the output of amplification stage 250 istransmitted prior to the analog switch 262 to the microphone statusdetector 33. The output of amplification stage 250 is also used in theMICIN signal for a speech synthesizer 400 which will be described inconjunction with FIG. 7a. The microphone status detector 33 utilizes anop amp 33d which has its first input coupled to the signal comingdirectly from the mouthpiece 32. The second input to op amp 33d is asignal which is processed through circuit 33b, amplifier 33a and circuit33c to give an average level of the signal level at the microphone.Circuit 33b is a filter which comprises diode 268, resistor 270,capacitor 272 and resistor 274 coupled as shown in FIG. 6b. The filteredsignal is then passed through amplifier 33a to circuit 33c whichcomprises a variable threshold voltage generator. The variable thresholdvoltage generator circuit 33c comprises diodes 276 and 278, resistor 280and variable resistor 282. Variable threshold voltage generator circuit33c transmits a signal to comparator op amp 33d which serves as areference level to compare with the unfiltered signal coming out of themicrophone. The output of comparator op amp 33d is transmitted throughresistor 284 into latch 33e, which is coupled as shown in FIG. 6b to a+5 voltage source. Latch 33e has its CLR pin connected to the inverseSPRESET signal generated by gate array 10i. The output of latch 33e istransmitted from the Q pin and through resistor 286 to create signalMICDET which is transmitted to programmable I/O 10h shown on FIG. 6a.

The telephone line interface 38 is shown on FIG. 6c. Telephone lineinterface 38 comprises a current detector 38a which is coupled to thering input from the telephone line. The current detector 38a comprises aparallel connection of a first optical coupling 296, a resistor 288 anda second optical coupling 292. The first optical coupling 296 comprisesa light emitting diode 295 and a transistor 297. The second opticalcoupling 292 similarly comprises a light emitting diode 291 and atransistor 293. The current detector 38a operates to detect current ineither the positive or negative direction through the telephone line.Current in the positive direction in the telephone line will cause theREVERT+ signal to be active, while current in the negative direction inthe telephone line will cause the REVERT- signal to be active. Whencurrent in the positive direction exist in the telephone line, diode 295will emit light which will cause transistor 297 to turn on, and willactivate the REVERT+ signal. Current in the negative direction in thetelephone line will similarly cause the REVERT- signal to be activated.The optical couplings 296 and 292 allow for the current detector 38a todetect current in the telephone line while still remaining electricallyisolated from the telephone line as is required by FCC regulations.

A resistor 302 and a capacitor 304 are connected in series between thering input and the tip input from the telephone line. This RC couplingis also required by FCC regulations. Resistor 302 and capacitor 304allow the telephone company to detect that a device is connected to thetelephone line at the particular location. A gas discharge tube 305 iscoupled between the TIP and RING inputs and ground and is used toprotect the circuitry from lightening discharges on the phone line.Telephone line interface 38 further comprises a hook relay 38b. Hookrelay 38b comprises individual relays 306 and 308 connected to the RINGand TIP inputs respectively. Individual relays 306 and 308 arecontrolled by the microprocessor control system 10.

Telephone line interface 38 further comprises isolation transformer 38cwhich is a transformer included in the system to comply with FCCrequirements that the telephone electronics must be electricallyisolated from the telephone line electronics. As shown on FIG. 6b, theTXAUDIO signal enters the isolation transformer 38c and is therebytransmitted to the telephone line. The TXAUDIO signal is generated bysummer 60 which is shown on FIG. 6a.

Telephone line interface 38 further comprises a balancing network 38d.Balancing network 38d comprises a parallel coupling of a resistor 301and a capacitor 303 coupled to ground. Balancing network 38d creates anRLC balancing network comprising the capacitor 303, the resistor 301 andthe isolation transformer 38c. The balancing network is used to balancethe impedance of the telephone line interface with the impedance of thetelephone line.

Telephone line interface 38 further comprises the audio path 38e whichis coupled to the isolation transformer 38c. Audio path 38e is coupledto ground through a resistor 305 and a capacitor 307. The audio signaltransmitted from isolation transformer 38c passes through a capacitor309 and a resistor 311 before being input into an audio buffer 38f.Audio buffer 38f comprises an op amp 313 coupled to a resistor 315 and acapacitor 317 as shown in FIG. 6c. Op amp 313 is coupled to a +2.5voltage source. The output of audio buffer 36f is the RXAUDIO signalwhich is transmitted to the modem 30 shown on FIG. 6a and theIntellistar transmit module 42 which will be described in conjunctionwith FIGS. 7a and 7b. The RXAUDIO signal is attenuated when the TONEOUTsignal is active. The TONEOUT signal is transmitted from the DTMFgenerator 36 shown on FIG. 6a. The TONEOUT signal passes through aresistor 323 and activates a transistor 321 which is connected to groundand the RXAUDIO signal through a capacitor 319. After the RXAUDIO signalhas passed through capacitor 319, the signal is transmitted to callstatus detector 28.

Also shown on FIG. 6c is the incoming ring detector 37. Incoming ringdetector 37 comprises a comparator 310 which has a first input coupledto the RING input of the telephone through a resistor 316, a capacitor316 and a capacitor 318. The first input of comparator 310 is connectedto a +5 volt supply through a resistor 320 and is coupled to groundthrough a resistor 324. A second input of comparator 310 is coupled tothe TIP input through a resistor 314 and a capacitor 312. The secondinput of comparator 310 is coupled to ground through a resistor 322. Theoutput of the comparator 310 passes through a diode 332 and is coupledto a +5 volt supply through the parallel connection of a diode 328 and aresistor 326. The output of diode 332 generates the inverse RING signalwhich is coupled to ground through a capacitor 330. The inverse RINGsignal is transmitted to programmable I/O 10h to inform microprocessorcontrol system 10 that a ringing signal has been detected on thetelephone line.

FIG. 7a is a schematic representation of the components of theIntellistar receive module 42, the Intellistar system controller 48 andthe Intellistar transmit module 40. Generally, the components shown inFIGS. 7a, 7b and 7c serve as a slave microcomputer control system whichis operationally peripheral to the remainder of the phone, but which isresident in the local telephone terminal. Referring to FIG. 7a, a speechsynthesizer 400 is shown which may comprise, for example, a Toshiba TC8830 speech synthesizer chip. Speech synthesizer 400 stores speechmessages in digital memory and is capable of recording and playing backthese messages. Speech synthesizer 400 uses three RAM chips 402, 404 and406. REM chips 402, 404 and 406 may comprise for example, Hitachi 62256low power 32 K×8 RAMs. RAMs 402, 404 and 406 interface with speechsynthesizer 400 through address bus A0-A14 and data bus D0-D7. RAM chips402, 404 and 406 are powered by the VBAT battery backed power signal.The speech synthesizer 400 selects a specific RAM chip using the inverseCE1, inverse CE2 or inverse CE3 signals.

The speech synthesizer 400 is controlled by the Intellistar systemcontroller 48 through the P0-P3 bus. The Intellistar system controller48 comprises a microprocessor 414 which will be discussed in conjunctionwith FIG. 7b. In addition to the P0-P3 bus, microprocessor 414 alsotransmits to speech synthesizer 400 the inverse RD signal, the inverseACL signal and the inverse WRSP signal. The inverse RD signal is a readenable control signal. The inverse ACL signal is a control signal whichresets the speech synthesizer. The inverse WRSP signal is an additionalread/write control signal generated by microcomputer 414. The MICINsignal is transmitted from the mouth piece 32 and is input to the C1 pinof speech synthesizer 400 after passing through a resistor 401 and acapacitor 402. The MICIN signal is an audio signal transmitted from themicrophone 32 which may be recorded.

The XIN and XOUT pins of speech synthesizer 400 are coupled to a crystal403 and to ground through capacitors 405 and 407. The crystal 403 isused to generate a clock signal for speech synthesizer 400 and generatea signal through an inverter 409 to clock a latch 408. The latch 408 iscoupled to a +5 volt power supply as shown in FIG. 7a, and is used tosynchronize the inverse WRS signal from microcomputer 414 to the inverseWRSP signal transmitted to speech synthesizer 400. Speech synthesizer400 also generates a SPOUT signal which is transmitted to a summer 58ashown on FIG. 7c.

Referring now to FIG. 7b, the microprocessor 414 is shown and maycomprise, for example, a GTE 65SC151 microcontroller chip. Themicrocomputer 414 is coupled to the address bus A0-A15, and the data busD0-D7. It also generates the control signals contained in the P0-P3 busthrough its PC0-PC3 pins. The inverse RDS signal is transmitted to theinverse RD pin of speech synthesizer 400 from the PA5 pin ofmicrocomputer 414. The microcomputer 414 generates controls signals LA,SH, ST and DF which are transmitted to components of the switch array 54shown on FIG. 7c.

Microcomputer 414 is coupled to a RAM 410 which may comprise, forexample, an 8 K×8 static RAM. RAM 410 is used to store program memoryand is coupled to the microcomputer 414 through the address bus A0-A12and the data bus D0-D7.

An EPROM 412 is coupled to microcomputer 414 through address bus A0-A13and data bus D0-D7. EPROM 412 may comprise, for example, a 16 K×8 EPROMwhich is used to store the boot program for microcomputer 414.

The RAM 410 and the EPROM 412 are selected and enabled by an inverseRAMW signal, an inverse MEMDE signal, an inverse RAMCS signal and aninverse EPROMCS signal. These control signals are generated by chipselect logic 411 shown on FIG. 7b. Chip select logic 411 comprisesinverters 413, 415 and 417, and NAND gates 419, 421, 423 and 425, whichare coupled as shown in FIG. 7b. Chip select logic 411 uses the Esignal, the Q signal and the R/W signal generated by microcomputer 414to enable RAM 410 and EPROM 412.

Microcomputer 414 also generates the inverse VWRB signal and the inverseVRDB signal from its PBO and PB1 pins respectively. The PB2 pin iscoupled to the EXCLK pin of modem 30 shown on FIG. 7c. The PB3 throughPB5 pins are coupled to a DTMF receiver 52 shown on FIG. 7c. The PB6 pinis used to enable a call status detector 50 shown on FIG. 7c. The PB7pin generates the inverse WRS signal which is transmitted to the latch408 shown on FIG. 7a. The PCO through PC3 pins generate the PO throughP3 control bus which controls speech synthesizer 400 and call statusdetector 50. The PC4 pin transmits the inverse MINT signal to theprogrammable I/O 10h. The LA1 signal is received from gate array 10i onpin PC5 of microcomputer 414. The PC6 pin is used to generate the VDATAsignal which is connected to the programmable I1O 10h and gate array10i. VDATA is a bidirectional data line for communication between thesystem processor and the Intellistar system processor. The CLK pintransmits a clock signal to the call status detector 50 and the DTMFreceiver 52 shown on FIG. 7c. The PC7 pin is coupled to the DATA pin ofmodem 30 shown on FIG. 7c. The inverse of NMI is connected to the VCLKsignals which is generated by the gate array 10j. Call status tonegenerator 56 is resident on microcomputer 414 and generates a signalfrom the CALL STATUS pin which is transmitted to summer 58a shown onFIG. 7c.

Referring now to FIG. 7c, call status detector 50 may comprise, forexample, a Silicon Systems 75T982 call status detector chip. Call statusdetector 50 is used to detect specific frequencies such as a busy tone,dial tone, a ring tone, or other tones that are associated with thetelephone line. Call status detector 50 is coupled to the RXAUDIOAsignal which is received from telephone line interface 38f at the AINpin. Call status detector 50 utilizes a parallel connection of aresistor 427 and a crystal 429 which are coupled to the XIN and XOUTpins. The crystal 429 oscillates at 3.58 megahertz and is used fortiming functions within the call status detector 50. This timebase isalso used by microcomputer 414 and DTMF receiver 52. The call statusdetector 50 is coupled to the microcomputer 414 through its DET1, DET2,DET3, DET4 and OE pins.

The RXAUDIOA signal transmitted from telephone line interface 38 is alsoinput into the DTMF receiver 52 shown on FIG. 7c. The RXAUDIOA signal isinput into the AIN pin through a capacitor 431. DTMF receiver 52 maycomprise, for example, a Silicon Systems 75T202 DTMF receiver chip. DTMFreceiver 52 detects the presence of DTMF signals in the RXAUDIOA signal.The DTMF receiver 52 is coupled to the microcomputer 414 through itsCLRDY, DV, EN, D1, D2, D4, D8 and XIN pins.

The RXAUDIOA signal from the telephone line interface 38 is alsotransmitted to the RXA pin on modem 30. Modem 30 may comprise, forexample, a 1200 band phase shift keyed Bell 212 protocol modem, such asa Silicon Systems 75T212. The TXDM and RXDM signals are used by modem 30to communicate serial data to the gate array 10e. Modem 30 also receivesan 11 megahertz clock signal from oscillator 108. Modem 30 transmits asignal from its TXA pin into a summer circuit 58b which forms a portionof the summer 58 shown on FIG. 2.

Modem 30 is coupled to microcomputer 414 shown on FIG. 7b through itsEXCLK, DATA, inverse RD, inverse WR, A0, A1 and A2 pins. The RESET pinis coupled to a KRESET signal which is generated by a reset generator462. The reset generator 462 shown on FIG. 7c may comprise for example aTI 7705 reset generator chip. The reset generator 462 is coupled to theRESET and VRES signals from the power supply and from gate array 10irespectively. Reset generator 462 generates the RESET signal and theKRESET signal used to reset the system.

The path of the RXAUDIOA audio signal originates from telephone lineinterface 38 and is used in several devices shown on FIG. 7c. TheRXAUDIOA audio signal is first input into call status detector 50, whichmonitors the signal to detect various frequencies associated with thetelephone line. The RXAUDIOA signal is also input into DTMF receiver 52which is used to detect the presence of DTMF signals used for telephonedialing.

The RXAUDIOA signal is also input into a portion of switch array 54indicated as 54a on FIG. 7c. Switch 54a comprises an analog switch 420which is controlled by the LA control signal generated by microcomputer414. If the analog switch 420 is closed, the RXAUDIOA signal will passthrough the 20 dB attenuator 62 which comprises a resistor 442. Thesignal will then enter a portion of summer 58 labeled as 58a on FIG. 7c.

The RXAUDIOA signal is also input into a switch 54b which also forms aportion of switch array 54. Switch 54b comprises an analog switch 422which is controlled by the DF control signal generated by microcomputer414. When analog switch 422 is closed, the RXAUDIOA signal istransmitted directly back to the controlled ear piece 26 as the RXAUDIODsignal which is shown entering analog switch 266 on FIG. 6b.

The summer 58a sums three separate signals. The first signal is theattenuated audio signal coming from 20 dB attenuator 62. The secondinput signal is from the call status tone generator 56 which is residenton microcomputer 414. This signal is labeled CALL STATUS on FIGS. 7b and7c, and is connected to ground through resistor 460. The DTMF signal istransmitted through a capacitor 454 and a resistor 452 to a first inputof an op amp 448. The op amp 448 is coupled in parallel to a capacitor446 and a resistor 444. The final input signal to the summer 58a is theSPOUT signal generated by the speech synthesizer 400 shown on FIG. 7a.The SPOUT signal comprises the audio messages generated by the speechsynthesizer 400. The SPOUT signal is coupled to ground through aresistor 458 and is transmitted to the first input of op amp 448 througha capacitor 456 and a resistor 450.

The output of op amp 448 is transmitted to switch 54c which forms a partof switch array 54. Switch 54c comprises an analog switch 426 which iscontrolled by the SH control signal generated by microcomputer 414. Whenswitch 426 is closed, the summed audio signal from 58a is transmitteddirectly to the controlled ear piece 26 as the RXAUDIOD signal. Theoutput of summer 58a is also transmitted to a switch 58c which comprisesan analog switch 424 controlled by the ST control signal generated bymicrocomputer 414. When analog switch 424 is closed, the audio signalfrom summer 58a is transmitted to a second stage of summer 58 labeled58b. Summer 58b operates to sum the audio signal from summer 58a and thetransmitted signal from modem 30. The output of summer 58b istransmitted as TXAUDIOA signal to summer 60 shown on FIG. 6a. Summer 58bcomprises an op amp 434 coupled to a +2.5 volt supply. Op amp 434 iscoupled in parallel to a resistor 436. The signal from switch 58c isinput into op amp 434 through a capacitor 440 and a resistor 438. Thesignal from modem 30 is input into op amp 434 through a capacitor 430and a resistor 432.

Collect and Direct 0+ Calls

Aspects of the telephone system constructed in accordance with thepresent invention may be better understood in connection with a flowchart representation of the steps necessary to perform these functions.FIGS. 8a-g represent the decision making process carried out bymicroprocessor control system 10 in carrying out the EZ collect anddirect 0+ call on a telephone constructed according to the presentinvention. Unless otherwise indicated, any decision made in the flowcharts occurs in microprocessor control system 10.

FIG. 8a comprises the beginning series of flow chart steps for the EZcollect and direct 0+ telephone call conversion technique of the presentinvention. An important technical advantage of the present invention, isthe ability of the local telephone station to take a call which isintended to be billed to a remote location and convert the call to acall format which is billed by the telecommunications system to thelocal telephone station. This enables the owner of the local terminal tobill for the call. For example, a patron may place a collect call on thetelephone. Ordinarily the collect call would be billed directly by theprimary telephone company to the destination number, provided the callwas accepted. According to the teaching of the present invention,however, the local telephone station changes the access format of thenumbers input into the telecommunications network so that the localtelephone station is billed for the call. In this manner, the owner ofthe local telephone station can bill for all types of calls placed fromthe station.

In the case of a collect call or a credit card phone call, the localtelephone station receives the destination number and billinginformation and places the call in a 1+ format. In another aspect of thepresent invention, the telephone could place a call placed using a 950exchange and also convert the call to a 1+ format. This type of accessformat is known as a feature group B access format. A telephoneconstructed according to the teachings of the present invention cansimilarly convert a call placed using a feature group D access formatusing a 10XXX prefix. The telephone of the present invention can also beprogrammed to convert calls placed using all forms of charge accountsfrom bank cards to gas cards. The telephone of the present invention canrecognize and convert any similar call placement access formats and allsuch formats are intended to be included within the scope of the presentinvention. The actions of the telephone station described in conjunctionwith the EZ collect and credit card phone calls would be substantiallyidentical for any call placement access format. Due to the great numberof these possible access formats, only the exemplary EZ collect andcredit card phone calls will be described in detail.

The program is initiated at 500 and a decision is made at 502 as towhether or not the receiver is off hook. If the answer is no, theprogram loops back and waits for the receiver to go off hook. Thereceiver off hook decision is made by the key pad hook switch 24.

If the receiver was off hook, the program flow turns the dial tone on tothe earpiece at step 504. Step 504 is accomplished by the telephone lineinterface 38 providing an audio path to the earpiece 26. Program flowthen goes to step 506 where microprocessor control system 10 collectsthe digits of the telephone number as the patron dials them on keypad24. A decision is then made at step 508 based upon the digits collectedin step 506 as to whether the call is a 0+ call, meaning that moredigits were dialed after a 0. If more digits were dialed after thepatron dialed a 0, the call is a 0+ call and the program flow proceedsto step 510 where the microprocessor control system 10 generates a"bong" tone to the earpiece 26.

Step 510 is accomplished by using a synthesized bong tone generated byspeech record/playback generator 44 and transmitting this tone throughan audio path through switch array 54 to earpiece 26. The bong tonewould then be heard by the patron, queing him to enter a telephonecredit card number if he so desires. Program flow then proceeds to step512 where a decision is made based on whether or not the patron hasentered a calling card. The program flow waits a predetermined amount oftime for the patron to enter a credit card number and if he does,program flow proceeds to CFD which is shown on FIG. 8b.

At step 512, if the patron does not enter a telephone credit cardnumber, program flow proceeds to step 514 where another decision is madewhere microprocessor control system 10 checks to see if the 0+ EZcollect call feature has been enabled in this particular telephone. Thisis done by microprocessor control system 10 testing an enable bit whichis stored in rate memory 16. If the telephone is not enabled to place 0+or EZ collect calls, program flow would route the call to a liveoperator. At step 514, if the telephone was enabled to accept 0+ EZcollect calls, program flow proceeds to EZC which is shown on FIG. 8e.

At decision block 508, if microprocessor control system 10 determinesthat the call was not a 0+ call, program flow would proceed to decisionblock 518 where microprocessor control system 10 would determine if thecall was a coin call, meaning that the digits that were dialed were not0+ but were a 1+ or direct dial call. If this is true, then program flowwould proceed to normal call processing which was described earlier. Atstep 518, if the microprocessor system 10 decides that the call is not acoin call, the call is a 0- call. In this instance, program flowproceeds to step 520 where microprocessor control system 10 tests anenable bit contained in rate memory 16 to determine if the 0- EZ collectcall feature of the telephone is enabled.

If this test bit indicates to microprocessor control system 10 that thefeature is not enabled, program flow would proceed to route the call toa live operator. If the feature has been enabled in the telephone,program flow would proceed to place the call using the EZ collectfeature. This is shown on the flow chart where program flow proceedsthrough EZC shown on FIG. 8e.

Referring now to FIG. 8b, program flow proceeds from CFD to step 516. Atstep 516, the first digit of the telephone credit card number iscollected through keypad 24. Program flow then proceeds to decisionblock 522 where microprocessor control system 10 determines if the firstdigit collected was a zero. If the first digit was a zero, program flowproceeds to EZC which is shown on FIG. 8e. If the first digit of thetelephone credit card number was not a zero, program flow proceeds tostep 524 wherein microprocessor control system 10 collects the remainingdigits of the telephone credit card number from keypad 24. The digits ofthe telephone credit card number are stored in stack RAM 46 containedwithin microprocessor control system 10.

Program flow then proceeds to decision block 526 wherein microprocessorcontrol system 10 compares the digits of the telephone credit cardnumber entered by the patron to a list of card numbers which have beenverified in the recent past. If the card number has already beenverified, microprocessor control system 10 will find it listed in thememory, and the program flow will proceed to ZTO which is continued onFIG. 8c.

An important technical advantage of a telephone constructed according tothe teachings of the present invention is the telephone's ability tolocally store billing numbers which have been validated. Because of thiscapability a user of a particular telephone station making multiplecalls using the same billing number need not wait for the number to berevalidated. This capability greatly reduces the time necessary toprocess some calls and thereby greatly enhances the convenience of thetelephone for users.

Referring again to FIG. 5b, if the card number has not recently beenverified, program flow proceeds to step 528 wherein microprocessorcontrol system 10 utilizes speech synthesizer 44 to play back aprerecorded speech message into earpiece 26 which instructs the patronto wait a predetermined time for his call to be verified. Step 528 alsoincludes the verification process which is shown independently in flowchart form in FIG. 11. Program flow then proceeds to decision block 530wherein microprocessor control system 10 tests a flag which was setduring the verification process dependent on whether the card was ableto be verified. If the verification was not successful, the call wouldthen be routed to a live operator who could attempt to verify the card.

If the verification was successful, program flow proceeds to step 532where microprocessor control system 10 determines whether theverification process determined that the card number was valid. If thecard was not valid, program flow proceeds to decision block 534 whereinmicroprocessor control system 10 tests a counter in its stack RAM todetermine if this is the third invalid card number entered by thispatron. If this is the first or second invalid card number entered bythe patron, program flow proceeds to block 536 wherein microprocessorcontrol system 10 utilizes speech synthesizer 44 and speech memory 46 toenunciate an audio message into earpiece 26 to ask the patron to enter acard number again. Program flow then proceeds to GB which reentersprogram flow on FIG. 8a prior to block 510. If at decision block 534,microprocessor control system 10 determines that this is the thirdinvalid card number entered by this patron, the call would be routed toa live operator.

If at decision block 532, microprocessor control system 10 determinesthat the verification process determined the card number was valid,program flow proceeds to block 538 wherein the card number is stored inRAM memory contained within microprocessor control system 10. This listof valid card numbers is updated in order to reduce the number ofvalidation accesses that the telephone must attempt. The card numberscontained in this memory are held for a period of three days in order toallow a patron to place multiple telephone calls using the same cardnumber within a short period of time more quickly and more conveniently.After the card number is placed in memory, program flow proceeds to ZTOwhich is continued on FIG. 8c.

Referring now to FIG. 8c, program flow proceeds from ZTO which flowsfrom steps 526 and 538 on FIG. 8b. Program flow proceeds to branch ZTOonly if the card number has been verified. Program flow then proceeds toblock 540 wherein microprocessor control system 10 uses informationstored within its own RAM and information stored in rate memory 16 toturn the 0 plus number into a 1 plus number. Program flow then proceedsto block 542 wherein microprocessor control system 10 uses telephoneline interface 38 to take the telephone line off hook and draw centraloffice loop current. Program flow then proceeds to block 544 whereinmicroprocessor control system 10 dials the number through the telephoneline interface 38 by using DTMF generator 36.

Program flow then enters a loop formed by decision blocks 546 and 548.In decision block 546, microprocessor control system 10 uses the callstatus detector 28 and call status detector 50 to detect whether thecalled party has answered. If the called party has not answered, programflow proceeds to decision block 548 where microprocessor control system10 determines if the patron has gone on hook by polling the keypad andhook switch 24. If the patron has gone on hook, program flow proceeds tobranch point COH which reenters program flow on FIG. 8a. If the patronhas not hung up the telephone, program flow stays in this loop untileither the party has answered in decision block 546 or the patron hasgone on hook in decision block 548.

When the called party answers at decision block 546, program flowproceeds to decision block 550 wherein microprocessor control system 10looks for intercept signals through the call status detector 28. If suchintercept signals are detected, program flow proceeds to block 552wherein microprocessor control system 10 takes the telephone lineinterface 38 back on hook, terminating the call. Program flow thenproceeds to branch point COH which reenters program flow on FIG. 8a.

If in decision block 550, microprocessor control system 10 did notdetect any intercept signals, program flow proceeds to block 554 whereinmicroprocessor control system 10 generates a billing record which isstored in call record memory 11. Program flow then proceeds to branchpoint UBR which is continued on FIG. 8d.

Also shown on FIG. 8c is branch point CDI which is reentering programflow from FIG. 8d. Program flow proceeds from CDI to block 539 whereinmicroprocessor control system 10 collects the digits of the telephonenumber dialed by patron on keypad 24. Referring to FIG. 8d, program flowproceeds from branch point UBR to decision block 556, whereinmicroprocessor control system 10 polls hookswitch 24 to determine if thepatron has gone on hook. If the patron has gone on hook, program flowproceeds to block 558 which closes the billing record and then proceedsto branch point COH which reenters the program flow on FIG. 8a.

If at decision block 556, the patron had not gone on hook, the programflow proceeds to decision block 560 where microprocessor control system10 decides whether the call is an EZ collect call. If the call is not anEZ collect call, program flow proceeds to block 562 whereinmicroprocessor control system 10 checks keypad 24 to determine if thepatron has dialed a number sign for a chain call. This is a commonmethod for a patron to place another call using the same card numberwithout having to go back on hook and redialing the card number.

If at decision block 560 the call was an EZ collect call, or if atdecision block 562 the patron had not dialed a number sign for a chaincall, program flow proceeds to decision block 564 which determines ifthe programmed elapse time has expired. The programmed elapse time isdetermined by microprocessor control system 10 by using an internalclock and rate memory 16 for a particular call. If the programmed elapsetime has expired, program flow proceeds to block 566 which updates thebilling record in call record memory 11 and records the new time.Program flow then proceeds back to decision block 556. If at decisionblock 564, the programmed elapse time had not expired, program flowwould proceed directly to decision block 556.

If at decision 562 the patron had dialed a number sign indicating achain call, program flow would proceed to block 568 whereinmicroprocessor control system 10 would close the billing record storedin call record memory 11. Program flow would then proceed to block 570wherein microprocessor control system 10 would terminate the call usingtelephone line interface 38. Program flow then proceeds to branch pointCDI whereby program flow returns to FIG. 8c.

Referring now to FIG. 8e, branch point EZC, program flow proceeds fromblocks 520 and 514 on FIG. 8a and from block 522 FIG. 8b. In thisprogram branch, the patron was attempting either a 0- collect call or a0+ EZ collect call. Program flow proceeds from branch point EZC to block572 wherein microprocessor control system 10 utilizes speech synthesizer44 to enunciate a prerecorded digitized message that instructs thepatron to press the digit one on keypad 24 to place an automated collectcall or to press the digit zero for a live operator. This prerecordedmessage is stored in speech memory 46 and is routed to earpiece 26 bymicroprocessor control system 10 through switch array 54.

Program flow then proceeds to decision block 574 wherein microprocessorcontrol system 10 utilizes keypad 24 to determine if any key was pressedby the patron. If no key was pressed, program flow proceeds to decisionblock 576 wherein microprocessor control system 10 determines if toomuch time has elapsed between the enunciation of the message in block572 and the key being pressed by the patron. If too much time haselapsed, program flow proceeds to route the call to a live operator. Iftoo much has not yet elapsed, program flow proceeds back to decisionblock 574 to again check to see if a check has been pressed in keypad24.

Once the patron depresses a key in keypad 24, program flow proceeds toblock 578 wherein microprocessor control system 10 determines if the keypressed was, a zero. If the key depressed was a zero, program flowproceeds to once again route the call to a live operator. If the keydepressed was something other than zero, program flow proceeds todecision block 580 which determines if the original call that was placedand stored in memory in microprocessor control system 10 was a 0- call,meaning that no additional digits after the zero were dialed. If thecall was a 0- call, then program flow proceeds to block 582 whereinmicroprocessor control system 10 again using speech synthesizer 44 andswitch array 54 enunciates a message stored in speech memory 46 intoearpiece 26 which requests the patron to dial his desired number.

Program flow then proceeds to block 584 where microprocessor controlsystem 10 collects the digits of the destination number from keypad 24.If the original call placed was not a 0- call or after the destinationnumber is collected in block 584, program flow proceeds to block 586where the microprocessor control system again uses the speechrecord/playback generator 44 and speech memory 46 to enunciate throughthese audio switch array 54 into the earpiece 26 a phrase similar to"your name will now be recorded, please say your name after the tone."Program flow then proceeds to block 588 wherein microprocessor controlsystem 10 uses speech synthesizer 400 to generate a single tone into theearpiece 26 to alert the patron that his name is to be recorded.

Program flow then proceeds to block 590 wherein the microprocessorcontrol system 10 uses the speech record/playback generator 44 to recordfrom the mouthpiece 32 and digitize the audio signal coming from themouthpiece 32 into the speech memory RAM 46. This recording process isdone for three seconds. Program flow then proceeds to block 592 whereinmicroprocessor control system 10 instructs the speech record/playbackgenerator 44 to enunciate a phrase similar to "your recorded name is"and playback the freshly recorded name of the patron through audioswitch array 54 into earpiece 26. In an alternate embodiment of thepresent invention, the user's name is not recorded but merelytransmitted directly to the called party after a temporary audio path isestablished.

Program flow then proceeds to decision block 594 wherein microprocessorcontrol system 10 tests an enable flag stored in rate memory 16 to seeif the verification process has been enabled by the user. If theverification process has been enabled, program flow proceeds to block596 wherein the microprocessor control system 10 uses the speechsynthesizer 44 in conjunction with speech memory 46 to enunciate amessage similar to "please wait one moment for your call to beverified."

Block 596 also includes the verification process illustrated in flowchart form in FIG. 11. Program flow then proceeds to decision block 598where microprocessor control system 10 tests to see if the verificationwas good or bad. If the verification was not good, program flow proceedsto block 600 where the microprocessor control system 10 using the speechgenerator 34 enunciates a message into the earpiece 26 such as "this isnot a billable number" and instructs the patron to "please hang up."Program flow then proceeds to block 602 wherein the microprocessorcontrol system 10 waits for the patron to hang up. Once the patron hashung up, the program flow proceeds to branch point COH which reentersthe program flow on FIG. 8a. If at decision block 594 the verificationprocess was not enabled, or if at decision block 598 the verificationprocess was determined by the microprocessor control system 10 to havebeen successful, program flow proceeds to block 604 whereinmicroprocessor control system 10 uses algorithms contained in programRAM to change the 0+ or 0- call into a direct dial call.

Program flow then proceeds to block 606 wherein microprocessor controlsystem 10 using telephone line interface 38 takes the line off hook andusing DTMF generator 36 dials the destination number. Program flow thenproceeds to branch point WA which is continued on FIG. 8f.

Referring now to FIG. 8f, program flow proceeds from block 606 to branchpoint WA and on to decision block 608. At decision block 608,microprocessor control system 10 uses call status detector 28 and callstatus detector 50 to determine if the call party has answered. If noanswer has occurred, program flow proceeds to block 610 whereinmicroprocessor control system 10 again utilizes call status detector 28and to detect if any intercepts have occurred. If intercepts haveoccurred, program flow proceeds to block 612 which terminates the call.Program flow then proceeds to block 614 wherein microprocessor controlsystem 10 polls hook switch 24 and waits for the patron to hang up thetelephone. When the patron hangs up the telephone, program flow proceedsto branch point COH which reenters the program flow on FIG. 8a. If atdecision block 610 no intercepts have been detected, program flowproceeds to decision block 616 wherein microprocessor control system 10once again polls hookswitch 24 to determine if the patron has gone onhook. If the patron has gone on hook, program flow proceeds to branchpoint COH and reenters the program on FIG. 8a. If at decision point 616the patron has not gone on hook, program flow loops back to decisionback 608 to once again test to see if the called party has answered.

When at decision point 608 the called party answers, program flowproceeds to block 618 wherein microprocessor control system 10 usingspeech synthesizer 44 and speech RAM 46 enunciates a message to earpiece 26 and down the telephone line through telephone line interface38. This message tells the called party that he has a collect call,enunciates the patron's name, and instructs the called party to dial oneif he wishes to accept the collect call or dial zero and hang up if hedoes not wish to accept the collect call. The message contained in block618 on FIG. 8f is only an example of what might possibly be enunciatedto the called party. An alternate message could move the replay of thepatron's name to the very beginning of the message to prevent the calledparty from hanging up as soon as he hears a computer on the other end ofthe line.

Program flow then proceeds to block 620 wherein microprocessor controlsystem 10 initiates a two-second waiting sequence. Program flow proceedsthen to decision block 622 wherein microprocessor control system 10 usesDTMF receiver 52 to determine if a DTMF 0 has been detected. If a DTMF 0was not detected, program flow proceeds to block 624 whereinmicroprocessor control system 10 again uses the DTMF receiver 52 todetermine if a DTMF 1 has been detected. If no DTMF 1 has been detected,program flow proceeds to decision block 626 wherein microprocessorcontrol system 10 utilizes call status detector 28 to determine if anyintercept signals have been detected. If an intercept is detected indecision block 626, program flow proceeds to block 628 wheremicroprocessor control system uses telephone line interface 38 toterminate the call. Program flow then proceeds to block 630 wheremicroprocessor control system 10 pulls hookswitch 24 to wait for thepatron to hang up the telephone. Once the patron has hung up thetelephone, program flow proceeds to branch point COH and program flowreenters the flow chart on FIG. 8a.

If, at decision point 626, no intercept signals have been detected,program flow would proceed to decision block 632 wherein microprocessorcontrol system 10 would determine if the two second waiting period hadelapsed. If two seconds had expired, program flow proceeds to branchpoint S2 which is continued on FIG. 8g. If at decision block 632, thetwo second waiting period had not expired, program flow would proceed todecision block 633, where microprocessor control system 10 would checkto see if the patron or the called party has hung up the phone. Ifneither party has hung up, program flow returns to decision block 622where the microprocessor 10 once again tests for the detection of a DTMF1 or a DTMF 0 tone.

In decision block 622, if the microprocessor control system utilizingthe DTMF receiver 52 detects a DTMF 0, program flow proceeds to block634 wherein microprocessor control system 10 utilizes telephone lineinterface 38 to disconnect the telephone line. Program flow thenproceeds to block 636 where microprocessor control system 10 utilizesspeech synthesizer 44 and speech RAM 46 to enunciate a message to thepatron informing him that his collect call was not accepted. Programflow then proceeds to block 638 wherein microprocessor control system 10polls hookswitch 24 and waits until the patron hangs up. Program flowthen proceeds to branch point COH and reenters the flow chart on FIG.8a.

In decision block 624, if a DTMF 1 tone was detected, program flowproceeds to block 640, wherein microprocessor control system 10initiates a billing record in call record memory 11. This billing recordis marked to indicate that this call is an EZ collect call and not a 0+telephone call. Program flow then proceeds to branch point UBR whichreenters the flow chart on FIG. 8d.

Referring now to FIG. 8g, program flow proceeds from decision block 632to branch point S2 after the two second waiting period has expired.Program flow then proceeds to block 642 wherein microprocessor controlsystem 10 again uses the speech synthesizer 44 and speech memory RAM 46to replay a message to the called party. The message indicates that thecalled party has an automated collect call from the patron and toinstruct the called party that he must dial a one to accept the call orto dial a zero and hang up if he does not wish to accept the call.

Program flow then proceeds to block 644 wherein microprocessor controlsystem 10 initiates a fifteen second waiting period. Program flow thenproceeds to decision block 646 wherein microprocessor control system 10utilizes DTMF receiver 52 to determine if a DTMF 0 has been detected. Ifa DTMF 0 is detected, program flow proceeds to branch point RJC whichreenters the program on FIG. 8f at block 634. If at decision block 646no DTMF 0 is detected, program flow proceeds to decision block 648wherein microprocessor control system 10 once again utilizes DTMFreceiver 52 to determine if a DTMF 1 has been detected. If no DTMF 1tone has been detected at decision block 648, program flow proceeds todecision block 652 wherein microprocessor control system 10 determinesif the fifteen second waiting period has expired. If the fifteen secondwaiting period has not expired, program flow proceeds to decision block653 where microprocessor control system 10 again checks to see if eitherparty has hung up the phone. If neither party has hung up the phone,program flow returns to decision block 646 where microprocessor controlsystem 10 once again determines if either a DTMF 0 has been detected ora DTMF 1 has been detected. If at decision block 648 a DTMF 1 wasdetected, or if at decision block 652, the fifteen second waiting periodexpires, program flow proceeds to block 650 wherein microprocessorcontrol system 10 generates a billing record in call record memory 11.Program flow then proceeds to branch point UBR which reenters the flowchart on FIG. 8d.

Under the method illustrated by FIG. 8g, if a called party fails to takeany action and the fifteen second waiting period expires, the calledparty is deemed to have accepted the call. The reason for doing this isthe existence of many rotary telephones that DTMF receiver 52 cannotdetect.

An alternate embodiment of the present invention uses a voicerecognition system to detect if the called party has accepted the call.A further embodiment of the present invention merely waits a specifiedperiod of time before completing the call. If the called party does nothang up within this period of time, he is assumed to have accepted thecall. These and other similar methods of detecting the acceptance of thecall by the called party are intended to be included within the scope ofthe present invention.

Speech File Generation

FIG. 9 represents in flow chart form the speech file generation processwhich is represented in block diagram form in FIG. 3. The process flowstarts at block 660 and proceeds to block 662 wherein a speaker uses atape recorder 70 shown in FIG. 3 to record all the appropriate phrasesnecessary on tape. Process flow then proceeds to block 664 where thetape recorder 70 plays back one phrase at a time into the audiodigitizer 72. Process flow then proceeds to block 666 where the phraseis moved from the audio digitizer to a phrase file. Process flow thenproceeds to decision block 668 which determines if there are any morephrases to be digitized.

If at decision 668 there are more phrases to be digitized, process flowloops back to block 664 and digitizes the next phrase. If there are nomore phrases to be digitized at block 668, process flow proceeds toblock 670 wherein the operator of the system using host computer 76assigns event numbers to the phrases in a definition file. The eventnumbers provide a mapping system for the telephone to tell which phrasesare used in which event in the telephone. Process flow then proceeds toblock 672 wherein the user of the host computer 76 utilizing a programdeveloped by IntellicalL takes all of the individual phrase files andcombines them into one speech file with a directory at the beginning ofthe speech file to indicate where each of the phrases start and what itsevent mapping number is. Process flow then ends with the resultingproduct being a complete speech file on disk ready to be downloaded intoa particular telephone.

Speech File Downloading

FIG. 10 illustrates in flow chart form the process by which the speechfiles that were generated in the process illustrated in FIG. 9 aredownloaded into telephones in the field. Process flow starts at 680 andproceeds to block 681 wherein the user invokes a program developed byIntellicalL called INET on a host computer 76. The host computer 76 usedin FIG. 10 may or may not be the same computer utilized to generate thespeech files. Once the speech files have been loaded on to a diskette,the diskette may be transferred to any compatible computer to completethe downloading process into the telephones in the field.

Process flow proceeds to block 682 where through the host computer 76the user selects a telephone or telephones to call. Process flow thenproceeds to 683 wherein the INET software calls the pay telephone in thefield. Process flow proceeds then to decision block 684 where the hostcomputer determines if a connection has been made with the telephone inthe field. If no connection is made, process flow loops back to block682 where either the user manually selects another telephone to call, orif the original selection was for batch mode, the program wouldautomatically proceed to the next telephoned call.

If at decision block 684 the connection was successfully made, processflow would proceed to block 685 wherein the host computer 76 determinesif the particular telephone which has been called has a VPP boardinstalled. The VMP board comprises Intellistar transmit module 40,Intellistar receive model 42 and Intellistar system controller 48 shownin FIG. 1. If the host computer 76 determines that there is no VMP boardinstalled, process flow proceeds to block 686 wherein the host computerwould present the user a menu which would not contain the speech filedownload option. Process flow would then proceed in block 687 toaccomplish any other INET command that the user selected includingexiting beyond that program. If at decision block 685, the host computerdetermines that a VMP board was installed in the particular telephone,process flow proceeds to block 688 where INET would present the userwith a menu of possible INET functions which would include the speechfile download option.

Process flow then proceeds to decision block 689 where the host computerdetermines if the user selects the speech file download option. If theuser did not select the speech file download option, process flowproceeds to block 694 and accomplishes any other INET commands selectedby the user including exiting the INET program. If the user selected thespeech file download option at decision block 689, process flow wouldproceed to block 690, which would prompt the user to enter the speechfile name. Process flow then proceeds to block 691 where the hostcomputer 76 would open the named speech file.

Process flow proceeds to block 692 where a block of data from the openedspeech file is transmitted to the telephone in the field. Theinformation transmitted to the telephone in the field is received bymodem 30 and microprocessor control system 10 would store the block ofdata in the appropriate place in speech memory 46 shown in FIG. 3.Process flow then proceeds to decision block 693 where the host computer76 determines if there is any more data blocks to be transmitted. Ifthere are more data blocks to be transmitted, process flow loops back toblock 692 and those blocks are transmitted. If there are no more blocksto be transmitted, process flow returns to block 688 which once againpresents the user with a menu including the speech file download option.

Credit Card Verification

FIG. 11 illustrates in flow chart form the various methods in which atelephone constructed in accordance with the teaching of the presentinvention verifies a telephone billing account number for use in makinglong distance telephone calls. FIG. 11 shows in greater detail blocks528 on FIG. 8b and 596 on FIG. 8e.

Program flow begins at block 700 and proceeds to decision block 702where microprocessor control system 10 consults rate table memory 16 todetermine if the validation interface computer system (VICS) has beenenabled. If the VICS verify system is enabled, program flow proceeds toblock 704 where microprocessor control system 10 uses telephone lineinterface 38 and DTMF generator 36 to dial the VICS number. The VICSthen answers the telephone inquiry and standard communications occurbetween the telephone and the VICS as were described in FIG. 4previously. The VICS then interacts using a high speed data link with avalidation data base service to determine if the billing number is validor invalid. The microprocessor control system 10 receives theinformation as to whether the billing number is valid or invalid, andstores that information in stack RAM. Program flow then proceeds todecision block 706 where the microprocessor control system 10 tests theinformation stored in stack RAM and sets a flag depending on whether thebilling number was valid or invalid, as shown by blocks 708 and 710respectively in FIG. 11.

If at decision block 702 the microprocessor control system 10 determinedthat the VICS verify system was not enabled, program flow would proceedto decision block 712, where microprocessor control system 10 wouldconsult rate memory table 16 to see if the call method of verificationwas enabled. If the call method of verification is not enabled, programflow proceeds to block 714 and the billing number is assumed valid. Ifat decision block 712 the call method verification process was enabled,program flow proceeds to decision point 713. At decision point 713 adecision is made whether the call was an 0+ credit card call or not. Ifthe call is not an 0+ credit card call program flow proceeds to block714. If the call is a 0+ credit card call, program flow proceeds toblock 716. At block 716, the telephone dials a preprogrammedverification number which is set up to always be busy or to neveranswer. This programmed number is stored in rate memory 16. Theprogrammed number can be up to 15 digits long which allows the telephoneto insert the prefix 10288 in front of the number so that the AT&Tsystem may be used even if the carrier prescribed to the telephone isnot AT&T. In one embodiment of the present invention, the telephone isprogrammed to call itself, a number which is guaranteed to be busy.

Program flow then proceeds to decision block 718 where microprocessorcontrol system 10 uses DTMF receiver 52 to detect a bong tone throughtelephone line interface 38. If no bong tone is detected, program flowproceeds to decision block 720 where microprocessor control system 10checks to see if a predetermined amount of time has elapsed waiting forthe bong tone. If the predetermined amount of time has elapsed, programflow proceeds to block 722 which routes the call to a live operator. Inthis case, the telephone assumes that something is wrong with thevalidation procedure.

At decision block 718, when a bong tone is detected, program flowproceeds to block 724 where microprocessor control system 10 dials thebilling number stored in its stack ram using DTMF generator 36. Programflow then proceeds to decision 726 where microprocessor control system10 uses call status detector 50 and call status detector 28 to senseeither busy tone or a ring back tone on the telephone line. If either ofthese tones is detected, a successful call has been placed using thebilling number, and therefore, the billing number is valid.

Program flow then proceeds to block 728 which would set a RAM flagcontained within microprocessor control system 10 that indicates to therest of the system that the billing number is valid. If no busy tone orring back tone is detected, program flow proceeds to decision block 730wherein microprocessor control system 10 determines if a programmedamount of time has elapsed waiting for the busy tone or ring back tone.Once the predetermined amount of time has elapsed, the telephone assumesthat successful calls cannot be placed with this billing number, and RAMflags are set within microprocessor control system 10 to inform the restof the system that the billing number is not valid at block 732. If thepredetermined amount of time has not elapsed, program flow loops back todecision block 726 where once again microprocessor control system 10tests for busy tone or ring back tones.

Voice Messaging System

FIGS. 12a-b represents in flow chart form the capability of a telephoneconstructed according to the teaching of the present invention tointeract with a voice messaging system which would enable a patron toleave a message for the called party if he was unable to complete hiscall. Program flow is initiated at block 750 and proceeds to decisionblock 752 which begins a loop wherein microprocessor control system 10tests hooks switch 24 to determine if the receiver is off the hook. Ifthe receiver is not off hook, program flow loops back and continues totest until the receiver goes off hook, at which point program flowproceeds to block 754 wherein the patron dials his destination numberthrough keypad 24. Block 754 also includes any necessary verificationsteps and any processing that might have been needed to be done in orderto place the call. These steps have been described in earlier FIGURES.

Program flow then proceeds to block 756 where microprocessor controlsystem 10 outpulses the appropriate numbers into the network in order toplace the call. Program flow then proceeds to decision block 758 wheremicroprocessor control system 10 tests to see if a preprogrammed numberof ring backs has occurred. This preprogrammed number is stored in ratememory 16 and as the ring backs occur, the counter which is contained inmicroprocessor control system 10 counts the number of rings and comparesit to the predetermined number. This preprogrammed number can be set bythe user, and determines when the voice messaging system initiates.

If the preprogrammed number of ring backs has not yet occurred, programflow proceeds to decision 760 wherein microprocessor control system 10uses call status detector 50 and call status detector 28 to determine ifthe line is busy. If the line is not busy, program flow proceeds todecision block 762 where microprocessor controls system 10 once againuses call status detector 28 and call status detector 50 to detect ifthe telephone has been answered. If the telephone is answered, programflow proceeds to block 764 where microprocessor control system 10connects a voice path and program flow proceeds to 766 which is thenormal call sequence depending on what type of call the patronoriginally placed. This could include, for example, an EZ collect call,a direct dial call 0+ or a coin call.

If at decision block 762 no answer was detected, then program flowproceeds to decision block 768 where microprocessor control system 10tests hookswitch 24 to determine if the patron has hang up thetelephone. If the patron has hang up the telephone, program flowproceeds to block 770 where microprocessor control system 10 terminatesthe call. The program flow then loops back to decision block 752 to waitfor the next call. If at decision block 768 the patron has not hung upthe telephone, program flow loops back to decision block 758 to wait forthe programmed number of ring backs, the detection of a busy signal, orthe detection of an answer.

If at decision 758 the preprogrammed number of ring backs has occurredor at decision 760 a busy signal was detected, program flow proceeds toblock 772 where microprocessor control system 10 which uses the speechrecord/playback generator 44 to enunciate a message through switch array54 into earpiece 26, which tells the patron to press 1 if he would liketo leave a voice message. Also, in block 772, the ring back or busysignal the patron was hearing from the phone line, is attenuatedapproximately 20 dB by attenuator 62. This is done so that the patroncan hear the telephone's instructions more clearly while still listeningto the phone line. Program flow then proceeds to branch point 1 whichcontinues on FIG. 12b.

Referring to FIG. 12b, program flow proceeds from branch point 1 todecision block 774 where microprocessor control system 10 checks keypad24 to see if the patron has pressed the one digit indicating that hewould like to leave a voice message. If the patron has not pressed theone digit, program flow proceeds to decision block 776 wheremicroprocessor control system 10 again checks call status detector 50and call status detector 28 to determine if the called party hasanswered. If the called party has not answered, program flow proceeds todecision block 778 wherein microprocessor control system 10 checkshookswitch 24 to determine if the patron has hung up. If the patron hashung up, program flow proceeds to block 780 where microprocessor controlsystem 10 terminates the call. Program flow then proceeds to branchpoint AG which reenters the program flow at decision block 752 on FIG.12a. If at decision block 778, the patron had not hung up the telephone,program flow loops back to decision block 774. If at block 774 the onedigit has been pressed, program flow proceeds to block 782 wheremicroprocessor control system 10 terminates the telephone call andplaces a call to the voice mail center. The number of the voice mailcenter is stored in rate memory 16.

Program flow then proceeds to decision block 784 where microprocessorcontrol system 10 waits a predetermined amount of time for the voicemail center to come on line. If the voice mail center does not answer,program flow proceeds to block 786 where microprocessor control system10 waits for the patron to hang up. Program flow then proceeds to branchpoint AG which reenters the program flow at decision block 752 on FIG.12a. An alternate embodiment could include an additional speech message,indicated at block 785, informing the patron that the voice mail centerhas not answered.

If at decision block 784 the voice mail center answers, program flowproceeds to block 788 where microprocessor control system 10 utilizesDTMF generator 36 to transfer information to the voice mail center aboutthe call. This information is required to enable the voice mail centerto know where the caller is trying to place the voice mail message aswell as identification information about the particular telephonecalling in for billing record purposes. Program flow would then proceedto block 790 where the patron would leave his name and message at thevoice mail center. This would all be controlled by the voice mail centerand the individual telephone would only have to enable the earpiece 26and the mouthpiece 32 so that the patron could interact with the voicemail center. Program flow then proceeds to block 791 wheremicroprocessor control system 10 uses coin return collect 22 to collectthe patron's money. Program flow then proceeds to block 786 and branchpoint AG which waits for the patron to hang up the telephone and loopsback to wait for the next call.

The voice mail center would then take the message the patron hadrecorded and ring the number the patron was trying to call, for example,every fifteen minutes for two to three hours to attempt to deliver thepatron's message. The actual voice mail center could be located in aremote location or it could be located within a localizedtelecommunications system, depending solely on cost effectiveness.

If at decision block 776, the called party has answered, program flowproceeds to block 792 where microprocessor control system 10 stops anyspeech message that may be playing. Program flow then proceeds to block794 where microprocessor control system 10 connects a voice path andprogram flow then proceeds to normal call processing depending on theparticular type of telephone call that was placed.

In summary, the present invention provides for a telecommunicationsstation which can perform locally a variety of functions which requiredprior systems to use a central office or centralized AOS. A paytelephone station constructed according to the teachings of the presentinvention can locally verify telephone billing account numbers and placea call using the verified number. In addition, the system can locallygenerate a billing record of the call which can later be retrieved tofacilitate the billing of the appropriate party to be charged for thecall.

A telephone constructed according to the teachings of the presentinvention enjoys the technical advantage of comprising a microprocessorcontrol system. This system enables the local station to use locallystored messages to interact with the patron during the patron's use ofthe station. Through the use of these messages, a patron can be promptedthrough the placing of a collect call. The local station can accomplishall the steps which once required the actions of a live operator. Thelocal station, at the user's request, can route the call to a liveoperator if the user so desires.

A telephone station constructed according to the teaching of the presentinvention can locally convert a telephone call entered by a user in avariety of billing formats into a direct dial call which is billeddirectly to the station. In this manner, the owner of the localtelephone station can bill for credit card calls, automatic collectcalls or calls placed using other billing methods placed by users of thestations.

The foregoing description uses preferred embodiments and processes toillustrate the present invention. However, changes and modifications maybe made in these embodiments without departing from the scope of thepresent invention. For example, the particular order of events ormessages relayed to a patron described herein could be modifieddepending upon a variety of circumstances. The content of the messagescould also be altered depending on local circumstances. These and othermodifications are intended to be included within the scope of thepresent invention.

While the present invention is illustrated by the embodiments in theabove detailed description, it is not limited to these embodiments butrather only by the scope and spirit of the claims which follow.

What is claimed is:
 1. A pay telephone station operable to be used by apatron placing a telephone call through a telecommunications network,the pay telephone station comprising:keypad circuitry operable toreceive a sequence of digits input by the patron, the sequence ofnumbers comprising an initial access format, an area code and adestination telephone number, the initial access format indicating tothe telecommunications network a telephone call to be billed to anaccount not associated with the pay telephone station; call conversioncircuitry operable to change the initial access format to an alteredaccess format indicating to the telecommunications network a telephonecall to be billed to an account associated with the pay telephonestation; call completion circuitry for placing the call through thetelecommunications network using said altered access format, said areacode and said destination telephone number; timing circuitry fordetecting the termination of the telephone call and for determining theduration of the telephone call; circuitry for storing the duration ofthe telephone call; circuitry for storing the area code and destinationtelephone number associated with the telephone call; circuitry forgenerating a bong tone operable to prompt the patron to enter an accountnumber prior to placement of the telephone call; circuitry for receivingan account number input by the patron using said keypad circuitry;circuitry for storing said account number; circuitry for receiving arequest for data stored in the pay telephone station through thetelecommunications network; circuitry for uploading a billing recordassociated with the telephone call upon receipt of a request for saidbilling record received through the telecommunications network, saidbilling record comprising the area code and destination number of thecall, the duration of the call and said account number; and each of saidcircuitries resident within a single payphone housing enclosing the paytelephone station.
 2. The pay telephone of claim 1 and furthercomprising:circuitry for storing voice prompts; and circuitry forselecting one of said stored voice prompts and playing said selectedvoice prompt for the patron in order to instruct the patron during theplacement of the telephone call.
 3. The pay telephone of claim 1 andfurther comprising:circuitry for recording the voice of the patron; andcircuitry for storing speech spoken by the patron and recorded by saidcircuitry for recording.
 4. The pay telephone of claim 1 and furthercomprising:circuitry for attenuating audible call progress signalsreceived from the telecommunications network such that prompts may beplayed for the patron simultaneously with said audible call progresssignals.
 5. A pay telephone station operable to be used by a patronplacing a telephone call through a telecommunications network, the paytelephone station comprising:keypad circuitry operable to receive asequence of digits input by the patron, the sequence of numberscomprising an initial access format, an area code and a destinationtelephone number, the initial access format indicating to thetelecommunications network a telephone call to be billed to an accountnot associated with the pay telephone station; call conversion circuitryoperable to change the initial access format to an altered access formatindicating to the telecommunications network a telephone call to bebilled to an account associated with the pay telephone station; callcompletion circuitry for placing the call through the telecommunicationsnetwork using said altered access format, said area code and saiddestination telephone number; timing circuitry for detecting thetermination of the telephone call and for determining the duration ofthe telephone call; circuitry for storing the duration of the telephonecall; circuitry for storing the area code and destination telephonenumber associated with the telephone call; circuitry for generating abong tone operable to prompt the patron to enter an account number priorto placement of the telephone call; circuitry for receiving an accountnumber input by the patron using said keypad circuitry; circuitry forstoring said account number; circuitry for receiving a request for datastored in the pay telephone station through the telecommunicationsnetwork; circuitry for uploading a billing record associated with thetelephone call upon receipt of a request for said billing recordreceived through the telecommunications network, said billing recordcomprising the area code and destination number of the call, theduration of the call and said account number; circuitry for storingvoice prompts; circuitry for selecting one of said stored voice promptsand playing said selected voice prompt for the patron in order toinstruct the patron during the placement of the telephone call;circuitry for recording the voice of the patron; circuitry for storingspeech spoken by the patron and recorded by said circuitry forrecording; circuitry for attenuating audible call progress signalsreceived from the telecommunications network such that prompts may beplayed for the patron simultaneously with said audible call progresssignals; and each of said circuitries resident within a single payphonehousing enclosing the pay telephone station.